May 2009

1MV Offset Clock-Tunable Monolithic 5-Pole Lowpass Filter: DN67 Design Notes (Linear Technology) (app note added 6/06)

Akerberg-Mossberg AM Second Order Lowpass inverting: (electronic design added 6/07)

Applications for a DC Accurate Lowpass Switched-Capacitor Filter: AN20 Linear Technology Discusses principles of operation of LTC1062 and helpful hints for its application. Various application circuits are explained in detail with focus on how to cascade two LTC1062s and how to obtain notches. Noise and distortion performance are fully illustrated.

Bach Second Order Lowpass non-inverting: (electronic design added 6/07)

Berka-Herpy BH Second Order Lowpass non-inverting: (electronic design added 6/07)

Centronics Port DA Converters and Lowpass Filter: (circuit / schematic design added 6/06)

Chebyshe Volt/Butterworth Filters: (electronic circuit added 7/03)

Chopper Amplifiers Complement a DC Accurate Low-Pass Filter: DN9 Design Notes (Linear Technology) (app note added 1/06)

First Order Lowpass I non-inverting: (electronic design added 6/07)

First Order Lowpass II non-inverting: (electronic design added 6/07)

Fliege Second Order Lowpass non-inverting: (electronic design added 6/07)

KHN Inverting Input Second Order Lowpass inverting: (electronic design added 6/07)

KHN Non-Inverting Input Second Order Lowpass non-inverting: (electronic design added 6/07)

LowPass Filter: Simple 3 coil, 4 capacitor Low Pass Filter. (circuit added 8/06)

Low-Pass Filter RFI Filter: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Lowpass, 30-kHz Bessel filter offers high performance for audio applications: 2/16/2006 EDN Design Ideas / (added 05/07) Careful selection of amplifiers and components helps achieve the lowest levels of noise and distortion for higher-order filter.

Low-Sensitivity, Lowpass Filter Design: National Semiconductor Application Note (app note added 2/06)

LTC1560-1: Tiny 1MHz Lowpass Filter uses No Inductors: DN169 Design Notes (Linear Technology) (app note added 1/06)

Mikhael-Bhattacharyya MB Second Order Lowpass non-inverting: (electronic design added 6/07)

Multiple Feedback MFB Second Order Lowpass I inverting: (electronic design added 6/07)

Multiple Feedback MFB Second Order Lowpass II inverting: (electronic design added 6/07)

OA-27: OA-27 Low-Sensitivity, Lowpass Filter Design: National Semiconductor Application Note (app note added 2/06)

Replace Discrete Lowpass Filters with the LTC1563 Zero Design Effort Two Item Bom and No Surprises: DN251 Design Notes (Linear Technology) (app note added 1/06)

Sallen-Key SK Second order Lowpass I non-inverting: (electronic design added 6/07)

Sallen-Key SK Second order Lowpass II non-inverting: (electronic design added 6/07)

SSB AF Filter: This is a simple filter that restricts the LF response a little as well providing quite a heavy HF roll-off. The prototype has enhanced a Yaesu FT101B that was only fitted with an AM IF filter. The IC is an LM358. (added 02/05)

Tow-Thomas TT Second Order Lowpass non-inverting: (electronic design added 6/07)

Twin-T Second Order Lowpass non-inverting: (electronic design added 6/07)

Unique Applications for the LTC1062 Lowpass Filter: AN24 Linear Technology Highlights the LTC1062 as a lowpass filter in a phase lock loop. Describes how the loop's bandwidth can be increased and the VCO output jitter reduced when the LTC1062 is the loop filter. Compares it with a passive RC loop filter. Also discussed is the use of LTC1062 as simple bandpass and band stop filter.

Active Filter has Wideband Tuning Range: 03/28/96 EDN-Design Ideas / (added 4/02)

First Order Lowpass III inverting: (electronic design added 6/07)

Adjustable Filter Provides Lowpass Response: 03/01/01 EDN-Design Ideas / (added 11/05)

Single Resistor Tunes Lowpass Filter: 08/21/03 EDN Design Ideas / (added 12/04) Any tunable, second-order, active RC-filter section requires at least two thoroughly matched variable resistors. But the lowpass implementation in Figure 1 provides for wide-range cutoff-frequency control using only a single variable resistor, R. In addition to the resistor, this filter comprises an operational amplifier, IC2, which serves as a unity-gain buffer; two capacitors, C1 and C2; ......

Lowpass Filter Discriminates Step Input from Noise: 09/18/03 EDN Design Ideas / (added 12/04) Numerous applications exist in industry, particularly with control systems, in which it is desirable to remove all but the lowest frequency components from a signal to effectively yield a dc voltage. This voltage may, for example, serve as a setpoint to a PID controller in a process-control or an HVAC application, in which the cable that is carrying the analog signal is exposed to a wide spectra......

Ultrasonic Switch: Circuit of a new type of remote control switch is described here. This circuit functions with inaudible (ultrasonic) sound. Sound of frequency up to 20 kHz is audible to human beings. The sound of frequency above 20 kHz is called ultrasonic sound. The circuit described generates (transmits) ultrasonic sound of frequency between 40 and 50 kHz. As with any other remote control system this cirucit too comprises a mini transmitter and a receiver circuit. Transmitter generates ultrasonic…. (added 10/05)

Ultrasonic Transducer Oscillator Circuit: ASCII format (added 7/02)

added 6/07)

First Order Highpass II non-inverting: (electronic design added 6/07)

First Order Highpass III inverting: (electronic design added 6/07)

First Order Highpass IV inverting: (electronic design added 6/07)

Fliege Second Order Highpass non-inverting: (electronic design added 6/07)

Highpass Filters Use Modified Equalelement Design: 05/24/01 EDN-Design Ideas / (added 5/03) Using a modified equal-element design for a lumped-circuit lowpass filter has several advantages over the well-known equal-element design (Reference 1 and Reference 2). The modified design exhibits superior passband performance with only modest degradation of stopband selectivity. Moreover, the ....

KHN Inverting Input Second Order Highpass inverting: (electronic design added 6/07)

KHN Non-Inverting Input Second Order Highpass non-inverting: (electronic design added 6/07)

Mikhael-Bhattacharyya MB Second Order Highpass non-inverting: (electronic design added 6/07)

Lowpass Filter has Improved Step Response: 02/19/04 EDN Design Ideas / (added 12/04) A common problem that arises when you design lowpass filters for signal conditioning is the filters' effect on the system's time-domain response. Because pushing the cutoff frequency lower slows the step response, the system may fail to recognize significant changes within a reasonable amount of time....

Precision Level Shifter has Excellent CMRR: 04/15/04 EDN Design Ideas / (added 1/05) Most designers make level shifters with op amps and 1%-tolerance discrete resistors. Discrete-resistor mismatching limits the op amp's CMMR (common-mode rejection ratio) to 40 dB, so you cannot use op amps in circuits that require high CMRR. Differential amplifiers contain precision matched internal resistors, so ICs such as the INA133 can readily achieve CMRRs of approximately 90 dB....

Brick-wall lowpass audio filter needs no tuning: 9/14/2006 EDN Design Ideas / (added 05/07) Gyrator supercapacitors eliminate the need for inductors in this 15-kHz filter.

LX1741/1742 Formula Calculator for AN22: MicroNote 1310 from Microsem (app note added 3/06)

Model Fixed Point DSP Arithmetic in C: 03/18/99 EDN-Design Ideas / (Schematic / circuit added 10/05) You can run initial high-level simulations of custom numerical algorithms, such as digital filters, using floating-point numbers in an environment such as C or Matlab. Unfortunately, you won't see include fixed-point effects, such as truncation due to limited precision and register overflow, until you use a Hardware Design Language (HDL), such as Verilog or VHDL. However, a technique that models these effects in C—the function "bit_limit" in Listing 1—provides faster execution and better portability than HDLs and allows early exploration of the trade-off between bus width and performance.

MW Active Antenna: This circuit is designed to amplify the input from a telescopic whip antenna. The preamplifier is designed to cover the medium waveband from about 550Khz to 1650Khz. The tuning voltage required is 1 to 12 volts and can be obtained from a 10k potentiometer connected to the 12 Volt power supply. RV1 is the gain control allowing weak signals to be amplified or strong signals to be attenuated. The control voltage is applied to gate 2 of TR1, a dual-gate MOSFET, the signal voltage applied via gate 1; the input signal being tuned via L1 and the two varicap diodes at the MOSFET's input and also by L2 and the varicaps at the MOSFET's drain terminal. Both tuned circuits provide high selectivity across the entire tuning range. To aid stability the MOSFET.... (added 10/05)

OA-26: OA-26 Designing Active High Speed Filters: National Semiconductor - Application Note (app note added 2/06)

Regenerating the DS1847 / DS1848 Resistor Calibration Constants: Maxim Application Notes / 1921 / Jun-08 (app note added 3/06)

Resistor Calculator : Luxeon Application Note (app note added 3/06)

RISC µP Implements Fast FIR Filter: 01/21/99 EDN-Design Ideas / (Schematic / circuit added 10/05) When it comes to implementing a fast FIR filter, current RISC µPs can compete with DSP µPs. The FIR algorithm continuously implements the following equation: N=n–1 Out=Sum[in(t[-]n)coeff(n)] N=0,....

Subwoofer Equalizer: The Linkwitz transform circuit is a hugely flexible way to equalize the bottom end of a sealed loudspeaker enclosure. A speaker that is corrected using this method is flat from below resonance to the upper limit of the selected driver. The low frequency roll off point is determined by the parameters of the transform circuit. Should the enclosure size be too small and cause a lump in the response before roll off, this is also corrected. A conventional active crossover network is then used to divide the subwoofer signal from the main channel signals. Note that there is also a separate spreadsheet calculator available for calculating component values for different situations not handled by the original circuit. (Electronic Circuit added 03/06)

Micro Power AM Broadcast Transmitters: In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a Class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable VFO with a capacitor/resistor combination. (added 4/02)

Micropower AM Band radio station: (circuit / schematic design added 6/06)

Pi Filter has Sharp Notch: Electronic Design 10/1/97 Simple filter network makes a great low-pass filter having a sharp notch just outside passband. Can be implemented as active filter using GIC circuit. Voted best of issue! (added 9/04)

Pi Section Coupler: (electronic circuit added 1/03)

RF Amplifier for Ferrite Bar Antennas: (electronic circuit added 1/03)

Unamplified Four Foot Box Loop: (electronic circuit added 1/03)

ZN414 AM Receiver: (circuit / schematic design added 6/06)

AM BCB Radio Receiver: (electronic circuit added 7/03)

AM Receiver for Aircraft Communications: (electronic circuit added 7/03)

AM Receiver: (schematic added 9/02)

AM-Receiver for Aircraft Communication (118.250MHz): (electronic circuit added 4/05)

Designing an AM Receiver For Low Power Wireless Systems Using the NEC UPC2768GR IC (7/22/96) : Application Note California Eastern Laboratories Doc #921 (app note added 6/06)

One-transistor Regenerative AM Receiver: A classic design revamped slightly. Features a single-transistor regen stage, and a range of 1000 miles with a 4-foot antenna. Perhaps the best "survival radio", yet. Now updated with speaker amplifier. (circuit design added 7/06)

Powerful AM Transmitter: (electronic circuit added 10/05)

Basic RF Transmitter for PIR Sensors: (diagram added 6/03)

Battery Low Voltage Beeper: This circuit provides an audible and visual low voltage warning for 12V battery powered devices. Idle current: 6ma Low Voltage Warning current: 15ma…. (schematic added 9/02)

Big Ben Sound: This circuit produces famous Big Ben sound. It produces "ding dong" sound when switched ON. Basically circuit alternates between two frequencies which are adjustable. This produces "ding-dong" sound. The first C (left) oscillates at about 1Hz. The second IC's tone is modulated by changing voltage at output of first IC..... (added 10/05)

ZN414 Portable AM Receiver: An AM portable radio receiver made from the ZN414 IC. The ZN414 IC has now been replaced by the MK484 which is identical in performance and pinout. (added 10/05)

AM DSB Transmitter for Hams: circuit diagram of simple double side band suppressed carrier (DSBSC) transmitter for hams. Circuit uses crystal oscillator, crystal can be switched for multi band operation. . (added 9/04)

AM Transmitter (circuitdb): circuit is deliberately limited in power output but will provide amplitude modulation (AM) of voice over the medium wave band. The circuit is in two halfs, an audio amplifier and an RF oscillator. (added 2/07)

AM Transmitter (zen22142): (design added 8/03)

AM Transmitter (zen22142): (electronic circuit added 4/05)

Micro Power AM Broadcast Transmitter: In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a Class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination. (added 4/02)

A 4 to 20 mA loop needs no external power source: 09/13/01 EDN Design Ideas / (added 11/05) The simple circuit in Figure 1 uses a low-current-drain MAX4073H amplifier to sense the current flowing through a 4- to 20-mA loop. The circuit senses the current through a 1Ω resistor with a fixed gain of 100 and uses no battery or dc power supply. The low current drain of the amplifier (0.

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 - Analog Devices Application Notes (added 2/06)

A User's Guide to I.C. Instrumentation Amplifiers: AN-244 - Analog Devices Application Notes (added 2/06)

AC Current Monitor: Senses high current-flow into power cables. No wire-cutting, three versions available. (circuit design added 3/05)

AC Line Current Detector: (circuit added 7/02)

Active Feedback IC Serves as Current Sensing Instrumentation Amplifier: 07/24/03 EDN Design Ideas / (Circuit / schematic design added 6/06) High-speed current sensing presents a designer with some significant challenges. Most techniques for sensing current involve measuring the differential voltage the current produces as it flows through a sense element, such as a resistor or a Hall-effect device. The differential voltage across the sense element is generally small and is often riding on a common-mode voltage that is considerably ......

Active feedback IC Serves as Current sensing instrumentation Amplifier: 07/24/03 EDN Design Ideas / (added 1/05) High-speed current sensing presents a designer with some significant challenges. Most techniques for sensing current involve measuring the differential voltage the current produces as it flows through a sense element, such as a resistor or a Hall-effect device. The differential voltage across the sense element is generally small and is often riding on a common-mode voltage that is considerably ......

AN-244: A User's Guide to I.C. Instrumentation Amplifiers: AN-244 - Analog Devices Application Notes (added 2/06)

AN-245: Instrumentation Amplifiers Solve Unusual Design Problems: AN-245 - Analog Devices Application Notes (added 2/06) Traditionally Considered Only for Transducer-Conditioning Applications, Instrumentation Amplifiers Bring Unique Performance Benefits to a Range of Other Applications as Well.

AN-282: Fundamentals of Sampled Data Systems: AN-282 - Analog Devices Application Notes (added 2/06)

AN-345: Grounding for Low-and-High-Frequency Circuits: AN-345 - Analog Devices Application Notes (added 2/06) Know Your Ground and Signal Paths for Effective Designs. Current Flow Seeks Path of Least Impedance-Not Just Resistance....

AN35 High-Side Current Sensing: Considerations and Applications for High-Side Current Monitoring: Zetec Semiconductors - Applications Notes - A guide for using the ZXCT range of products. Contained within the note are application ideas for extended supply ranges, a circuit for bi-directional current sensing and an over-current/short circuit protection circuit. Now updated and contained within AN39 (added 2/06)

AN39 Current Measurement Applications Handbook: Zetec Semiconductors - Applications Notes - This applications handbook explores how the requirements affect the design for AC and DC current measurement and the implications on cost and performance for different approaches. (added 2/06)

AN-539: Errors and Error Budget Analysis in Instrumentation Amplifier Applications: AN-539 - Analog Devices Application Notes (added 2/06) Describes a systematic approach to calculating the overall error in an instrumentation amplifier application.

AN-589: Ways to Optimize the Performance of a Difference Amplifier: AN-589 - Analog Devices Application Notes (added 2/06) This Application Note presents several ways to build and optimize the performance of a discrete difference amplifier. It also recommends amplifiers that will make the overall solution cost/performance competitive with monolithic instrument amplifiers.

AN-597: Current Feedback Amplifiers: National Semiconductor - Application Note (added 2/06)

AN-671: Reducing RFI Rectification Errors in In-Amp Circuits: AN-671 - Analog Devices Application Notes (added 2/06)

AN-683: Strain Gage Measurement using an AC Excitation: AN-683 - Analog Devices Application Notes (added 2/06)

AN-772: A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 - Analog Devices Application Notes (added 2/06)

AN-840: Development of an Extensive SPICE Macromodel for 'Current-Feedback' Amplifiers: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Analog input circuit Serves any microController: 12/20/01 EDN - Design Ideas / (Electronic circuit added 10/03) The simple ADC in Figure 1 is perfect for getting analog signals into a purely digital microcontroller. Using just five surface-mount parts, you can assemble it for less than 50 cents (1000), which is approximately half the cost of a single-chip-ADC approach in the same volume. Moreover, this design takes only one pin from the microcontroller to operate. .

Bias Voltage and Current Sense Circuits for Avalanche Photodiodes: AN92 - Linear Technology - Avalanche photodiodes, used in laser based fiberoptic systems, require high voltage bias and accurate, wide range current monitoring. Bias voltage varies from 15V-90V and current ranges from 100nA to 1mA, a 10,000:1 dynamic range. This publication presents various 5 volt powered circuits which meet these requirements. Appended sections detail specific circuit techniques and cover measurement practice.

1 In/4 Out Audiodistribution Amplifier : (electronic Circuit added 03/06)

1.5 Volt Amplified Ear: Useful to listen in faint sounds1.5-Volt Battery operation, includes electret microphone preAmplifier which runs from1.5-Volt DC and can directly drive32 Ohms impedance mini-earphones (added 9/04)

10 Watt Audio Amplifier: (electronic design added 6/07)

100 Watt Amp Circuit: Here is a simple and cheap amp to make. (added 10/05)

100 Watt Guitar Amplifier Mk2: (electronic Circuit diagram added 03/03)

100 Watt Guitar Amplifier: The original of the unit above. Retained for posterity, and has speaker box details (schematic added 6/07)

100 Watt RMS Amplifier: This is a100-Watt basic power amp that was designed to be (relatively) easy to build at a reasonable cost. It has better performance (read: musical quality) than standard STK module amps that are used in practically every mass market stereo receiver manufactured today. When I originally built this thing, it was because I needed a100 WPC amp and didn't want to spend any money. So I designed around parts I had in shop. (added 4/02)

101 Watt Guitar Amplifier: The original of the unit above. Retained for posterity, and has speaker box details (schematic added 6/07)]

15 Watt Amplifier: (electronic design added 6/07)

18 Watt Audio Amplifier: (electronic design added 6/07)

2 Channel Power Amplifier: 2-Channel Power Amplifier based on NTE1606. circuit is powered by a12V,10-Amp power supply. power of output channels is4 W connected to 8-ohm loudspeakers (added 2/07)

-/+ -0.1V Differential Amplifier Circuit using Zero Threshold EPAD MOSFETs: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

A Single Amplifier Precision High Voltage Instrument Amp: DN25 - Design Notes (Linear Technology) (added 1/06)

AC Coupling Instrumentation Amplifier Improves Rejection Range Of Differential Dc Input Voltage: 09/30/04 EDN Design Ideas / (added 12/04) The need for conditioning low-level ac signals in the presence of both common-mode noise and differential dc voltage prevails in many applications. In such situations, ac-coupling to instrumentation and difference amplifiers is mandatory to extract the ac signal and reject common-mode noise and differential dc voltage....

AN-257: Careful Design Tames High Speed Op Amps: AN-257 - Analog Devices Application Notes (added 2/06)

Amplifier And Current Source Emulate Instrumentation Amplifier: 11/13/03 EDN Design Ideas / (added 12/04) The classic three- or two-op-amp instrumentation-amplifier circuits are standard ways to amplify a small-amplitude differential signal contaminated with high common-mode noise. In some applications, the signal source is floating with high-series-output impedance and thus requires an appropriate high-input-impedance amplifier....

Brick-wall lowpass audio filter needs no tuning: 9/14/06 EDN Design Ideas / (added 10/06) Gyrator supercapacitors eliminate need for inductors in this 15-kHz filter.

Lowpass Filter uses Only Two Values: 07)/05/01 EDN Design Ideas / (added 12/04) In recent years, image-parameter design of LC filters has received new consideration (references 1 and 2). The composite lowpass filter uses interior constant-k full sections terminated by m-derived half-sections. For best passband response, you usually select m to equal 0.6. However, m=0.5 can still give useful filter performance while reducing the number of component values....

Active 2nd Order Filters: (electronic circuit added 7/03)

Butterworth Filters: (electronic circuit added 7/03)

Chebyshe Volt Bandpass Filter: (electronic circuit added 7/03)

Low Pass Active Filter: (electronic circuit added 7/03)

78 RPM and RIAA Phono Equaliser: Multi Standard 78 RPM and RIAA Phono Equaliser handles all "standards" (added 6/07)

Adjustable 60Hz Filter: to filter out any HUM that may be picked up by a noisy power supply or long wire connection (added 4/02)

Adjustable Audio Notch Filter: (schematic added 9/02)

Akerberg-Mossberg AM Second Order Notch inverting: (electronic design added 6/07)

Berka-Herpy BH Second Order Notch non-inverting: (electronic design added 6/07)

Build an Adjustable High Frequency Notch Filter: 02/06/03 EDN Design Ideas / (added 12/04) Although you can obtain universal, resistor-programmable switched-capacitor filters that are configurable as notch filters, most cannot operate at bandwidths higher than 100 kHz. Furr, typically 16to 20-pin packages do not include a continuous-time, antialiasing filter to prevent spurious signals from appearing at output....

Closing the Loop Deepens Notches: 05/07)/02 EDN Design Ideas / (added 12/04) Notch filters remove a single unwanted frequency from an input signal. They are also a vital component of pulse-shaping networks, such as time-averaging filters. You can tune a state-variable filter over a wide range by changing the time constants of its integrating amplifiers (references 1, 2, and 3). ...

CW Filters: (electronic circuit added 7/03)

Easy Parametric and Graphic Eq's Plus Peaks and Notches: (circuit / schematic design added 6/06)

Fliege Second Order Notch non-inverting: (electronic design added 6/07)

Helical Resonator Notch Filter: (electronic circuit added 7/03)

High Q Notch Filter: National Semiconductor Application Notes first published28-Jun-1996 (app note added 4/02)

High-Q 60-Hertz Notch Filter: This high-Q notch filter is based on the "Twin-T" design. It produces a very deep notch in the response curve at about 59.7 Hz. This is useful to remove 60-Hz hum and noise from audio recordings or live performances. Response is down over -60db at the center point. The LM3900 Norton opamp was chosen since it doesn't require extra components for single-supply operation.... (circuit design added 7/06)

KHN Inverting Input Second Order Notch non-inverting: (electronic design added 6/07

KHN Non-Inverting Input Second Order Notch inverting: (electronic design added 6/07)

LB-5: High Q Notch Filter: National Semiconductor Application Note (app note added 2/06)

Mikhael-Bhattacharyya MB Second Order Notch non-inverting: (electronic design added 6/07)

Notch Filter is DC Accurate: 03/02/95 EDN Design Ideas / (added 7/02)

Notch Filter is Insensitive to Component Tolerances: 03/02/00 EDN-Design Ideas / (added 2/06)

Notch Filter uses Only Lowpass Filters: 04/10/97 EDN Design Ideas / (added 6/06)

Notebook Power Supply has Two Outputs: 03/03/94 EDN-Design Ideas / (added 3/06) The notebook-computer supply in Fig 1 powers the 5V logic and derives an adjustable -24V supply for an LCD's backplane. The design uses only a high-efficiency buck regulator (Si9150) and an NMOS/PMOS, dual-power-FET chip set (Si9943), eliminating the extra parts required when you implement both supplies independently. Because of the low on-resistances of the dual FETs, this circuit can achieve better than 92% efficiency at 7.2V input and full-load output (7.6W)....

RC Notch Filter Twin T: The twin T notch filter can be used block an unwanted frequency or if placed around an op-amp as a bandpass filter. The notch frequency occurs where the capacitive reactance equals the resistance Xc=R and if the values are close, the attenuation can be very high and the notch frequency virtually eliminated. (added 4/02)

Reverse RIAA Equaliser: Test phono preamps for correct equalisation, or convert unused phono inputs. (circuit added 6/07)

Sallen-Key SK Second Order Notch non-inverting: (electronic design added 6/07)

Simple Easy Parametric and Graphic Eq's Plus Peaks and Notches: (circuit / schematic design added 6/06)

Switched-capacitor IC forms notch filter: 09/30/99 EDN-Design Ideas / (added 10/06)

Twin-T Second Order Notch I non-inverting: (electronic design added 6/07)

Twin-T Second Order Notch II non-inverting: (electronic design added 6/07)

Variable notch filter with both high and low pass filters: (schematic / circuit added 2/07)

1 Wire Barometer: (electronic diagram added 6/03)

12-Bit 8-Channel Data Acquisition System Interfaces to IBM PC Serial Port: DN35 Design Notes (Linear Technology) (app note added 1/06)

16-Channel 24-Bit Delta Sigma ADC Provides Small Flexible and Accurate Solutions for Data Acquisition: DN297 Design Notes (Linear Technology) (app note added 6/06)

1-Wire Barometer: circuit requires an additional power source or than that of 1-Wire network. MPX4115 requires about 7 ma of current. This is more than a 1-Wire network can provide without an elaborate circuit to store parasitic power from 1-Wire network for short burst of current for pressure measurements. Two voltage regulators are used to provide both 5.0 and 10.0 voltages from a source of DC power ranging from 12 to 24 volts. (added 2.07)

A 70-W S-Band Amplifier For MMDS and Wireless Data/Internet Applications (12/11/00) : Application Note California Eastern Laboratories Doc #932 (app note added 11/06)

Linkwitz Transform Circuit: The Linkwitz Transform circuit - an equaliser to provide extended bass response (circuit added 6/07)

Low-Sensitivity, Bandpass Filter Design with Tuning Method: National Semiconductor Application Note (app note added 2/06)

Method of Designing Multiple Order All Pole Bandpass Filters by Cascading 2nd Order Sections: AN27A Linear Technology Presents two methods of designing high quality switched capacitor bandpass filters. Both methods are intended to vastly simplify the mathematics involved in filter design by using tabular methods. The text assumed no filter design experience but allows high quality filters to be implemented by techniques not presented before in the literature. The designs are implemented by numerous examples using devices from LTC's SwitchedCapacitor filter family: LTC1060, LTC1061, and LTC1064. Butterworth and Chebyshev bandpass filters are discussed. (app note added 6/06)

Micro-power Band-pass Network: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Mikhael-Bhattacharyya MB Second Order Bandpass non-inverting: (electronic design added 6/07)

Multiple Feedback Bandpass Filter sound.au: This is the basis of an expandable equaliser and analyser or vocoder (schematic added 9/02)

Multiple Feedback Bandpass Filter: (electronic circuit added 7/03)

Multiple Feedback MFB Second Order Bandpass I inverting: (electronic design added 6/07)

Multiple Feedback MFB Second Order Bandpass II inverting: (electronic design added 6/07)

Narrow Band Audio Bandpass Filter: (electronic circuit added 7/03)

OA-28: OA-28 Low-Sensitivity, Bandpass Filter Design with Tuning Method: National Semiconductor Application Note (app note added 2/06)

Sallen-Key SK Second Order Bandpass non-inverting: (electronic design added 6/07)

Self Tune Filter: (electronic circuit added 7/03)

Simple Method of Designing Multiple Order All Pole Bandpass Filters by Cascading 2nd Order Sections: AN27A Linear Technology Presents two methods of designing high quality switched capacitor bandpass filters. Both methods are intended to vastly simplify the mathematics involved in filter design by using tabular methods. The text assumed no filter design experience but allows high quality filters to be implemented by techniques not presented before in the literature. The designs are implemented by numerous examples using devices from LTC's SwitchedCapacitor filter family: LTC1060, LTC1061, and LTC1064. Butterworth and Chebyshev bandpass filters are discussed. (app note added 6/06)

Single Op-Amp Bandpass Filter: A bandpass filter passes a range of frequencies while rejecting frequencies outside the upper and lower limits of the passband. The range of frequencies to be passed is called the passband and extends from a point below the center frequency to a point above the center frequency where the output voltage falls about 70%.... (added 2/07)

Tow-Thomas TT Second Order Bandpass inverting: (electronic design added 6/07)

Twin-T Second Order Bandpass inverting: (electronic design added 6/07)

Active 2nd Order Filters: (electronic circuit added 7/03)

Akerberg-Mossberg AM Second Order Highpass inverting: (electronic design added 6/07)

Berka-Herpy BH Second Order Highpass non-inverting: (electronic design added 6/07)

Butterworth Filters: (electronic circuit added 7/03)

Chebyshe Volt Bandpass Filter: (electronic circuit added 7/03)

Chebyshe Volt/Butterworth Filters: (electronic circuit added 7/03)

First Order Highpass I non-inverting: (electronic design

A Collection of Differential to Single-Ended Signal Conditioning Circuits for Use with the LTC2400 a 24-Bit No Latency Δσadc in an SO-8: AN78 Linear Technology This application note describes six low power differential-tosingleended signal conditioning circuits for LTC2400 No Latency ΔΣTM 24-bit ADC. These circuits offer customer a number of choices for conditioning differential input signals as low as 5mV to as high as ±2.5V, as well as operation on a single 5V or ±5V supplies. Each circuit description also covers circuit design and implementation techniques that can help preserve LTC2400's inherently high effective resolution. AN78 concludes with two circuits for digitizing temperature when using an RTD or Type S rmocouple.

A Two Wire Isolated and Powered 10-Bit Data Acquisition System: DN19 Design Notes (Linear Technology) (app note added 1/06)

Accelerometer Schematic: (diagram added 2/07)

Acquisition system is Programmable on the fly: 10/12/95 EDN-Design Ideas / (added 11/05) The programmable data-acquisition system in Fig 1 can take 333k samples/sec using a 3-µsec sampling ADC, IC3. Multiplexer IC1 and programmable gain amplifier (PGA) IC2 provide four truly differential channels and four decade gains of 1, 10, 100, and 1000. These features allow circuit to handle low-signal sensors without additional conditioning circuitry. The circuit does not require an S/H amplifier due to ADC's sampling structure. If you want to handle noisy and high-speed signals, you may need to add an antialiasing filter in front of ADC. The heart of system is a 4x4 register file, IC5, which essentially controls ....

Acquisition Times of the ADN2812: AN-757 Analog Devices Application Notes (app note added 2/06)

Ad-03: Effects of Aperture Time and Jitter in a Sampled Data: National Semiconductor Application Note (app note added 2/06)

ADC to PC interface Transfers data in nibbles : 12/09/99 EDN-Design Ideas / (added 6/06) -The circuit in Figure 1 uses a Centronics printer port to interface an eight-channel, 8-bit ADC to a PC. The circuit cuts cost of addressing and decoder circuitry and saves one expansion slot for interfacing. The design uses three of subport...

Addressable ADC: (electronic diagram added 6/03)

ADXL202 accelerometer to CV output: (diagram added 2/07)

AN-1041: CHANNEL LINK Moving and Shaping Information in Point-To-Point Applications: National Semiconductor Application Note (app note added 2/06)

AN-22: Integrated Circuits for Digital Data Transmission: National Semiconductor Application Note (app note added 2/06)

AN26(A-R) Interfacing the LTC1090/1/2: AN26 Linear Technology A collection of interface applications between various microprocessors/ controllers and LTC1090 family of data acquisition systems. The note is divided into sections specific to each interface. (app note added 2/06)

AN-281: Data Acquisition using Ins8048: National Semiconductor Application Note (app note added 2/06)

AN-282: Fundamentals of Sampled Data Systems: AN-282 Analog Devices Application Notes (app note added 6/06)

AN-383: Embedded Shock and Temperature Recorder: AN-383 Analog Devices Application Notes (app note added 2/06)

AN-578: RMS Calculations for Energy Meter Applications using the ADE7756: AN-578 - Analog Devices Application Notes (app note added 2/06) The document describes the implementation of an rms signal processing algorithm using the ADE7756 and a Microcontroller (PIC16C63) from Microchip.

AN-626: Using the AD7732/AD7734/AD7738/AD7739 Checksum Register: AN-626 - Analog Devices Application Notes (app note added 2/06)

High Input Impedance DC Summing Amplifier: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (app note added 2/06)

High Input Impedance Precision DC Summing Amplifier: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (app note added 3/06)

Low Voltage High Input Impedance Precision DC Summing Amplifier: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (app note added 2/06)

AN-214: Ground Rules for High Speed Circuits: AN-214 - Analog Devices Application Notes (added 2/06) Layout and Wiring Are Critical in Video Converter Circuits.

AN-282: Fundamentals of Sampled Data Systems: AN-282 - Analog Devices Application Notes (added 2/06)

AN-347: Shielding and Guarding: AN-347 - Analog Devices Application Notes (added 2/06) How to Exclude Interference-Type Noise. What to do and Why to do it-A Rational Approach

AN-357: Operational Integrators: AN-357 - Analog Devices Application Notes (added 2/06)

AN-358: Noise and Operational Amplifier Circuits: AN-358 - Analog Devices Application Notes (added 2/06)

AN-584: Using the AD813X Differential Amplifier: AN-584 - Analog Devices Application Notes (added 2/06) The AD813x differs from conventional op amps by the external presence of an additional input and output. The additional input, VOGM, controls the output common mode voltage.

AN-649: Using the Analog Devices Active Filter Design Tool: AN-649 - Analog Devices Application Notes (added 2/06)

AN-772: A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 - Analog Devices Application Notes (added 2/06)

27MHz toy car receiver: (Circuit / schematic design added 6/06)

500mW HF Linear Amplifier: (Circuit / schematic design added 6/06)

500w HF Linear Amplifier: (Circuit / schematic design added 6/06)

Active Antenna for HF-VHF-UHF: (Circuit / schematic design added 6/06)

Composite Amp Provides High Gain and Bandwidth: 04/28/94 EDN-Design Ideas / (Electronic Schematic / circuit added 04/02) The composite circuit in Fig 1 couples the output drive and slew rate of a current-feedback amplifier, IC2, with the low-noise and low-offset characteristics of a voltage-feedback operational amplifier, IC1. The circuit achieves gains as high as 1000, while showing little variation in frequency characteristics with gain. This circuit suits applications requiring high gain and wide dynamic range, such as ultrasound, radar, digital radio, and other high-noise applications....

Singlesideband Demodulator Covers the HF Band: 10/26/00 EDN-Design Ideas / (Circuit added 9/04)

Wideband Opamp Capable of Micropower Operation : National Semiconductor Application Note 24-Oct-2001 (added 1/03)

Analog Input Circuit Serves Any Microcontroller: 12/20/01 EDN Design Ideas / (added 10/03) The simple ADC in Figure 1 is perfect for getting analog signals into a purely digital microcontroller. Using just five surface-mount parts, you can assemble it for less than 50 cents (1000), which is approximately half cost of a single-chip- ADC approach in same volume. Moreover, this design takes only one pin from microcontroller to operate. .

LED Driver Delivers Constant Luminosity: 06/12/03 EDN Design Ideas / (added 12/04) The circuit in Figure 1 is similar in principle to that of a previous Design Idea (Reference 1) but offers improved, more reproducible performance. The output current is almost constant over an input-voltage range of 1.2 to 1.5V and is insensitive to variations of transistor gain. Transistors Q1 and Q2 form an astable flip-flop....

Network Imitates Thermocouples: 11/08/01 EDN Design Ideas / (added 12/04) Thermocouples find widespread use for temperature measurement in systems. During system design or testing, you must observe the system's response at different temperatures. However, it's inconvenient to heat a thermocouple every time you need to check a system's performance. You can use the simple trick of touching the thermocouple with a hot soldering iron, but this method provides only ... ...

Positive Feedback Yields Fast Amplifier with Precision DC Offset: 04/01/04 EDN Design Ideas / (added 1/05) Some signal-processing applications require a high-speed, low-noise, dc-coupled amplifier that incorporates a precision dc-offset adjustment. Examples include oscilloscopes, in which the offset adjustment typically acts as a "position" control), ADC-input gain blocks, and scanning-ion-beam-microscopy deflection circuitry....

Temperature Sensing with a Programmable Gain Amplifier: Microchip Application Note Published 26-Jun-03 (app note added 2/06)

TV/Radio Antenna Cable galvanic isolator: (electronic circuit added 8/03)

Using the AD7732/AD7734/AD7738/AD7739 Checksum Register: AN-626 - Analog Devices Application Notes (app note added 2/06)

Video Emitter uses Battery Power: 08/30/01 EDN Design Ideas / (added 12/04) The block diagram in Figure 1 shows how to make a cable-free, direct-video system. The system allows users to walk from booth to booth at an exhibition to interview people and to display the interviews in real time on three screens at key locations. You can use the small and simple system each time you need to capture image and sound on the run. ...

Anticipating timer switches before you push the button: 04/03/03 EDN-Design Ideas / (Electronic circuit added 10/03) (Editor's note: This Twilight Zone-worthy circuit will be the subject of an upcoming network sitcom, My Big Fat Anticipating Timer.) It happens to almost everyone that an apparatus or system should have been turned off a moment ago. The device in question could be the car heater, the air conditioner, the lights

Air Flow Detector #1: This simple circuit uses an incandescent lamp to detect airflow. With the filament exposed to air, a constant current source is used to slightly heat the filament. As it is heated, the resistance increases. As air flows over the filament it cools down, thus lowering its resistance. A comparator is used to detect this difference and light an LED. With a few changes, the circuit can be connected to a meter or ADC to provide an estimation on the amount of airflow. (Electronic Schematic / circuit added 4/02)

Airflow Monitor Protects Components: 09/28/95 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02)

Sensing Air Flow with the PIC16C781: Microchip Application Note - Published 30-Dec-02 (added 2/06)

TB044: Sensing Air Flow with the PIC16C781: Microchip Application Note - Published 30-Dec-02 (added 2/06)

Aircraft Receiver: (electronic circuit added 7/03)

AM Receiver for Aircraft Communications: (electronic circuit added 7/03)

AM-Receiver for Aircraft Communication (118.250MHz): (electronic circuit added 4/05)

AM2 circuit: (circuit / schematic design added 6/06)

Amplitude Modulation of the AD9850 Direct Digital Synthesizer: AN-423-Analog Device Application Notes (app note added 6/06)

Am-Receiver for Aircraft Communication (118.250MHz): (electronic circuit added 4/05)

Designing an AM Receiver For Low Power Wireless Systems Using the NEC UPC2768GR IC (7/22/96) : Application Note California Eastern Laboratories Doc #921 (app note added 6/06)

General Purpose RF Amplifier: (electronic circuit added 1/03)

How to Build a 300MHz AM RF Remote Control System: (circuit / schematic design added 6/06)

KD2BD ATV AM Video Modulator: video signal processing circuit that allows adjustment of video gain, video bias, sync and sync level (added 6/06)

Limiting Amplifier Forms AM Modulator: 12/07/95 EDN-Design Ideas / (added 4/02)

Voltage to Current Converter Drives White LEDs: 06/27/02 EDN Design Ideas / (added 12/04) You sometimes need to drive a white LED from one 1.5V battery. Unfortunately, the forward voltage of a white LED is 3 to 4V. So, you would need a dc/dc converter to drive the LED from one battery. Using the simple circuit in Figure 1, you can drive one white LED or two series-connected green LEDs, using only a few components....

Ways to Optimize the Performance of a Difference Amplifier: AN-589 Analog Devices Application Notes (app note added 6/06) This Application Note presents several ways to build and optimize the performance of a discrete difference amplifier. It also recommends amplifiers that will make the overall solution cost/performance competitive with monolithic instrument amplifiers.

Agilent TS-5400 Series II Automotive Electronics Functional Test System: Agilent Application Note (added 6/06)

AN-70-001 Fixed attenuators help minimize impedance mismatches: Application Note MiniCircuits.com (app note added 6/07)

Audio-test accessory isolates and matches loads: 3/16/06 EDN Design Ideas / (added 10/06) This low-cost, switchable, dual-impedance transformation circuit comprises a single conventional transformer and two minimum-loss pads.

Fixed attenuators help minimize impedance mismatches: AN-70-001 Application Note MiniCircuits.com (app note added 6/07)

High Input Impedance Precision DC Summing Amplifier: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

High-impedance voltmeter: An ideal voltmeter has infinite input impedance, meaning that it draws zero current from the circuit under test. This way, there will be no "impact" on the circuit as the voltage is being measured. The more current a voltmeter draws from the circuit under test, the more the measured voltage will "sag" under the loading effect of the meter, like a tire-pressure gauge releasing air out of the tire being measured...(schematic added 6/07)

Measuring Characteristic Impedance of Short Rambus Motherboard Traces and Small-Outline RIMMs: Agilent Application Note (added 6/06)

Variable Amplifier Impedance: idea of being able to vary the output impedance of a power amplifier (added 6/06)

40 Meter Popcorn Superhet Receiver: This schematic is a relatively low-cost CW superhet receiver with a 4.00 MHz Intermediate frequency. re is no AGC or RF gain control, however this receiver has good large signal handling capability. This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into headphones. Much of ideas/design of various stages must ... (added 02/05)

AN-502: Designing a Superheterodyne Receiver using an IF Sampling Diversity Chipset: AN-502 Analog Devices Application Notes (app note added 10/06) The AD6600/AD6620 Chipset Simplifies Receiver Design

HDT Technology Adds Power to CDMA Chip Set: RF Micro Devices Application Note TA0003 (added 02/05)

I.F. Amplifier: The I.F. transformer primary has 18 turns, the secondary winding has 4 turns. The capacitors across the IFT primaries are 82pF. The input/output transformer has 12 turns, tapped at 3 turns from ground. This transformer is wound on a ferrite core. The mosfets are 3SK45's. The diodes in the product detector are 1N34's. I use a six pole SSB filter from a scrap CB. The centre frequency is 7.8MHz. The -6db bandwidth is about 2.5KHz. (added 02/05)

Low Distortion IF Amplifier/ ADC Driver with Digitally Controlled Gain: Linear Technology LT5524 (app note added 02/05)

Tunable IF with TDA7000: The main motive of the mods was not that the circuit didn't work right, but were several tries to add some kind of frequency indicator to the receiver. The left RCA plug and associated components are witnesses to the last version, adding a FET buffer amplifier and taking signal from the oscillator coil. (added 02/05)

UltraLow Distortion IF Amplifier/ ADC Driver with Digitally Controlled Gain: Linear Technology LT5514 (app note added 02/05)

4 MHz Amplitude Modulated RF Source : A while back I needed an amplitude modulated signal source at 4 MHz. This circuit was literally thrown together with parts laying on the bench. I built it dead bug style on a piece of copper clad board. It should work with little or no modification, other than the selection of the crystal, at other frequencies. At lower frequencies you might have to increase the capacitor values to get it to oscillate, and at higher frequencies, you might have to reduce the capacitor values a little...(circuit added 6/07)

40 Meter Direct Conversion Receiver: (electronic (schematic / circuit added 11/06)

AM Broadcast Band Regenerative Receiver: (circuit / schematic design added 6/06)

Am Loop Antennas by Bruce Carter: (circuit added 9/04)

AM Radio PreAmplifier: (circuit added 9/04)

AM Receiver for Aircraft Communications: (electronic circuit added 4/05)

AM Receiver: (schematic added 9/02)

AM Transmitter #2: (design added 8/03)

AM/FM/SW Active Antenna: This circuit shows an active antenna that can be used for AM, FM, and shortwave SW. On the shortwave band this active antenna is comparable to a20 to30 foot wire antenna. This circuit uses receivers that use untuned wire antennas, such as inexpensive units and car radios. L1 can be selected for the application (added 4/02)

A Compact Algorithm using the ADXL202 Duty Cycle Output: AN-603 - Analog Devices Application Notes (added 2/06)

Algorithm Extracts Cube Root : 1/15/98 EDN Design Ideas / (Schematic / circuit added 10/05)

Algorithm Extracts Roots of Decimal Numbers: 04/29/99 EDN-Design Ideas / (Schematic / circuit added 10/05) "Algorithm extracts cube root" (EDN, Jan 15, 1998, pg 100) covers only the one-third power (cube root). In contrast, the C routine in Listing 1 calculates the Kth root (X1/K) of positive decimal numbers X. Both K and X can vary widely. You type in X, K, and an estimate of the root; the routine then calls the calcRoot function in the software program. Upon calculating the root, the routine prints on screen the number of iterations performed and the root result X1/K. The routine raises this result to the Kth power and displays the result so you can make a comparison with the original X. The algorithm applies a Newton-Raphson approach to the equation Y=X1/K. If you differentiate the equation and express it in recursive form, you obtain....

Algorithm Yields Precise Bessel Function: 11/09/95 EDN-Design Ideas / (Schematic / circuit added 10/05)

AN-603: A Compact Algorithm using the ADXL202 Duty Cycle Output: AN-603 - Analog Devices Application Notes (added 2/06)

White LED Driver provides 64 step logarithmic dimming: 06/10/04 EDN Design Ideas / (added 1/05) The circuit in this Design Idea is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3V source.

AN752: AN752 CRC Algorithm for Mcrf45x Read/Write Device: Microchip Application Note - Published 15-Mar-01 (added 2/06)

Composite Amplifier Improves Noise : 08/04/94 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02) Amplifying low-signal levels for signal processing often stretches a single op amp's abilities. A composite design can improve the input noise for detecting extremely small signals and can enhance output-drive ability. Both the op amp's noise terms and the thermal noise of the components limit the minimum noise in an op-amp-based design. Furthermore, amplifier noise figures are not at their minimum for low-impedance sources such as 50 Ohm. Using a transformer is a common technique to achieve matched input impedance for maximum power transfer. Fig 1 shows one example, which follows the transformer with a composite amplifier to achieve a lower input noise figure...

Low Noise Microphone PreAmplifier: (Electronic circuit added 7/03)

Low Noise Amplifier for Phase Noise Measurements: features less input noise than a 50 ohmresistor. (Electronic circuit added 7/03)

A Versatile Hybrid Synthesizer for UHF and Microwave Projects: Controlled by PC parallel port, this hybrid DDS/PLL synsizer delivers full-octave coverage between 1000 and 2000 MHz with sub-1 Hz resolution and commercial-quality phase-noise performance. (added 6/06)

Microwaves and RF Magazine Cover Feature: CEL and eRide Team to Provide Embedded GPS Solution : Application Note California Eastern Laboratories Doc #913 (app note added 6/06)

Ultrasonic radar: This is a very interesting project with many practical applications in security and alarm systems for homes, shops and cars. It consists of a set of ultrasonic receiver and transmitter which operate at the same frequency. When something moves in the area covered by the circuit the circuit’s... (electronic design added 6/07)

Unusual Radar Detector : (electronic (schematic / circuit added 2/05)

Yaesu FT 736R Doppler Compensation: (electronic (schematic / circuit added 2/05)

1 In/4 Out Audiodistribution Amplifier : (diagram added 6/03)

2 Wire Remote Microphone Amplifier : (diagram added 6/03)

40 MHz Programmable Video Op Amp: National Semiconductor Application Note (app note added 2/06)

741 Op-Amp Tutorial: (electronic design / schematic added 2/06)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 2/06)

A Simplified Test Set for Op Amp Characterization: National Semiconductor Application Note (app note added 2/06)

AB-3: Digital Nulling of Precision Op Amps: AB-3 Analog Devices Application Notes (app note added 6/06)

Amplifier Requires No DC Bias: 03/16/00 EDN-Design Ideas / (added 11/05) Intrinsically capacitive transducers and or high-impedance signal sources usually require ac coupling and a buffer amplifier to condition signal for furr processing. Buffers take many forms, but most of m compromise signal quality through use of external resistors that provide a dc path for input bias current. Recent improvements in op-amp technology allow ac-coupled inputs without need for bias resistors. The new op amps have inputs that operate within supply-voltage span. Some are CMOS, but many use complementary bipolar transistors. For latter, each input connects....

AN-1245: Unlimited Capacitive Load Drive Op Amp Takes Guess Work Out of Design: National Semiconductor Application Note (app note added 2/06)

100W Guitar Amplifier: (circuit / schematic design added 2/07)

12 Watt Valve Guitar Amp: (electronic diagram added 2/07)

220 Watt Power Amplifier: This is a building plan for an audio Amplifier with2 x220-Watt output power. Text is in Finnish. (added 3/06)

2304 and 3456 MHz Power Amplifiers: (electronic circuit added 4/05)

60 Watt into 8 Ohms Power Amplifier: A simple amp to build, uses commonly available parts and is stable and reliable (added 6/06)

AN-60-033 Enhanced Linearity in the HELA-10 Power Amplifier: Application Note MiniCircuits.com (app note added 6/06)

Design of Power Amplifier Using the UPG2118K (7/20/04) : Application Note California Eastern Laboratories Doc #957 (app note added 6/06)

Enhanced Linearity in the HELA-10 Power Amplifier AN-60-033: Application Note MiniCircuits.com (app note added 6/06)

100kHz to1GHz RF Power Detector: Linear Technology LTC5507) (app note added 02/05)

500W, Class E 27.12 MHz Amplifier Using A Single Plastic MOSFET: Application Note Microsemi-formerly Advanced Power Technology APT9903 ( app note added 2/07)

A 50 Mhz, 250w Amplifier Using Push-Pull Arf448a/B: Application Note Microsemi-formerly Advanced Power Technology APT9702A ( app note added 2/07)

A Simple Method to Reduce DC Power Consumption in CDMA RF Power Amplifiers Through the LMV225 and an Efficient Switcher: National Semiconductor Application Note (app note added 6/06)

Controlling TDMA Timeslot Power Levels using the Esg-D Series, RF Signal Generators: Aligent App Note (added 2/06)

General Purpose RF Amplifier: (circuit / schematic design added 6/06)

Generic VHF Power Amplifier: (electronic circuit added 7/03)

Behind the Switch Symbol: AN-355 - Analog Devices Application Notes (app note added 2/06) Use CMOS Analog Switches More Effectively When You Consider Them as Circuits

Mobile Solutions (Mp3 Cell Phone Pda Pmp): Pericom Semiconductor Application Brief # 046 ((app note added 02/05)

The Alexander Current-Feedback Audio Power Amplifier: AN-211 - Analog Devices Application Notes (app note added 2/06)

Anemometer Circuit: (schematic / circuit added 11/06)

Low-Cost Anemometer Fights Dust: App Note 844: Maxim IC (Circuit / schematic design added 6/06)

Self Heated Transistor Digitizes AirfLow: 03/14/96 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02)

6x6 Antenna Loop: (added 8/03)

Active Antenna for HF-VHF-UHF: (Circuit added 9/04)

AM Loop Antennas: (added 1/03)

Antenna Extension Provides Open Door Policy: 02/16/98 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02)

ANTENNProjects: (circuit added 7/02)

Long Loopstick AM Radio Antenna: Wound on a3-foot length of PVC pipe, the long Loopstick antenna was an experiment to try to improve AM radio reception without using a long wire or ground. It works fairly well and greatly improved reception of a weak station130 miles away. A longer rod antenna will probably work better if space allows. The number of turns of wire needed for the Loopstick can be worked out from the single layer, air core inductance formula: (Electronic Schematic / circuit added 4/02)

Q Multiplying Loop Antenna: (added 9/02)

Tesla Power Receiver: (circuit added 7/02)

Yagi Uda Antenna : (circuit added 7/02)

Astable Multivibrator 1: (Electronic Schematic / circuit added 4/02)

Flip Flop Flashers Buzzers Etc.: (Electronic circuit added 7/03)

Add Programmable Gain, Attenuation: AN-254 Analog Devices Application Notes (app note added 6/06) Simple CMOS Multiplying DAC Circuit Provides Digital Control of Gain and Attenuation of Analog Signal

AN-70-004 Digital Step Attenuators offer Precision and Linearity: Application Note MiniCircuits.com (app note added 6/06)

Digital Stereo Potentiometer: in PDF format, text in Finnish (added 4/02)

Precision Attenuator with Digital Control: (electronic Circuit / Schematic added 10/04)

Precision Divide by Two Analog Attenuator Needs No External Components: 03/17/05 EDN Design Ideas / (added 11/05) Many modern A/D converters offer only a 5V input range, and using these converters with a 65V or larger input signal gives the designer a problem: how to discard half of a good analog signal without introducing errors and distortion. To solve the problem, you can use an attenuator comprising two operational amplifiers and two resistors (Figure 1).

30 Ddm to +30 Ddm Audio Level Meter: circuit with balanced input and adjustable gain to drive needle type VU meter, uses special amplifier module from Op-Amp Labs (added 4/02)

Amplified Ear: (circuit added 9/04)

Arc welder sound simulator: (diagram added 2/07)

Audio Detector Circuit: (diagram added 2/07)

Audio graphic equaliser: (diagram added 2/07)

Audio Line Isolator #1: (electronic circuit added 1/03)

Audio Line Isolator #2: (electronic schematic added 8/02)

Audio Transformer #2: notes on using audio transformers for balanced signal interfacing (added 4/02)

Bluetooth Headset: Intersil Application Block Diagram (app note added 6/06)

AN-348: Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Notes (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

AN-581: Biasing and Decoupling Op Amps in Single Supply Applications: AN-581 Analog Devices Application Notes (app note added 2/06)

AN-60-034 Transient Protection of Darlington gain block Amplifiers: Application Note MiniCircuits.com (app note added 6/07)

AN-683: Strain Gage Measurement using an AC Excitation: AN-683 Analog Devices Application Notes (app note added 2/06)

Applications for a Switched-Capacitor Instrumentation Building Block: AN3 Linear Technology This application note describes a wide range of useful applications for LTC1043 dual precision instrumentation switched capacitor building block. Some of applications described are ultra high performance instrumentation amplifier, lock-in amplifier, wide range digitally controlled variable gain amplifier, relative humidity sensor signal conditioner, LVDT signal conditioner, charge pump F/V and V/F converters, 12-bit A/D converter and more. (app note added 6/06)

ADN2891 Evaluation Board: AN-762 Analog Devices Application Notes (app note added 2/06) This application note describes ADN2891 evaluation board.

100 Watt Guitar Amplifier Mk II: (schematic added 9/02)

AN-762: ADN2891 Evaluation Board: AN-762 Analog Devices Application Notes (app note added 2/06) This application note describes ADN2891 evaluation board.

Limiting Amplifier is Digitally Programmable: 06/04/98 EDN-Design Ideas / (added 11/05) Amplitude limiters are necessary in many systems, such as radar and FM receivers, for which the system cannot allow the amplitude of the signal to exceed the given positive, negative, or both limits. In the circuit in Figure 1, amplifier IC4B's maximum output is digitally programmable over ±2 to ±10V in 2n steps, where n is the number of bits of the DAC. IC1, a precision 10V reference, provides a full-scale reference current, IREF=VREF/R1=2 mA, to IC2, a multiplying DAC. IC3's output voltage, VL, is the sum of the product of the digital word and unipolar...

Aviation Band Receiver: (circuit added 9/04)

12 Volt Alarm Power Supply: (circuit / schematic design added 6/06)

4 Digit Keypad: (diagram added 6/03)

5 Zone alarm circuit MIT: (schematic added 2/07)

5 Zone Alarm Circuit: (electronic schematic added 8/02)

5 Zone Alarm System: (electronic design added 6/07)

5 Zone Alarm: Each zone uses a normally closed contact. se can be micro switches or standard alarm contacts (usually reed switches). Zone 1 is a timed zone which must be used as entry and exit point of building. Zones 2 5 are immediate zones, which will trigger alarm with no delay. Some RF immunity is provided for long wiring runs by input capacitors, C1-C5. C7 and R14 also form a transient suppresser. key switch acts as Set/Unset and Reset switch. For good security this should be .... (added 09/05)

A CMOS Single Zone Intruder Alarm: This circuit features automatic Exit and Entry delays - timed bell cut-off - and system reset. It has provision for normally-open and normally-closed switches - and will suit all of the usual input…(added 05/07)

A Simple Electronic Buzzer: This very simple circuit just uses a couple of resistors, a capacitor and easily available 555 timer IC. The 555 is setup as an astable multivibrator operating at a frequency of about 1kHz that produces a shrill noise when switched on. The frequency can be changed by varying 10K resistor. (added 10/06)

A Transistor Based - Single Zone Alarm: This circuit features automatic Exit and Entry delays - timed bell cut-off - and system reset. It has provision for normally-open and normally-closed switches - and will suit all of the usual input...(added 05/07)

Active IR Motion Detector: (diagram added 6/03)

Alarm Control Keypad: (circuit / schematic design added 6/06)

Alarm PSU: (circuit / schematic design added 6/06)

Alarm System: (design added 8/03)

Alarm Touched Triggered: (electronic Circuit diagram added 03/03)

Almost Ultrasonic Motion Sensor: (diagram added 6/03)

An SCR Based Burglar Alarm: (electronic design added 6/07)

Anit Theft Motorcycle Alarm: (schematic added 9/02)

Anti-Theft Alarm for Bikes: (circuit / schematic design added 6/06)

Anti-Theft Security for Car Audios: (electronic Circuit / Schematic added 10/04)

Automatic Intruder Alarm: (electronic design added 6/07)

Automatic Intruder Alarm: This is a simple single-zone burglar alarm circuit. Its features include automatic Exit and Entry delays and a timed Bell/Siren Cut-Off. It's designed to be used with the usual types of...(added 05/07)

Automatic Night Lamp with Morning Alarm: (electronic Circuit / Schematic added 10/04)

RIAA Equalized Stereo Phono Preamp: (circuit / schematic design added 6/06)

105 W 6 Channel Surround Sound: This reference design allows customers with limited knowledge of digital audio amplifiers to quickly build solutions, which meet Dolby, EMI and FTC standards, reducing the time-to-market for new consumer audio products. This 6 channel reference design, based on the TDA8925ST and TDA8926J power stages, is available with an output power of 5x15 W + 1x30 W. (circuit design added 3/05)

Surround Processor: Simple Surround Processor. This is built with only conventional parts, and digital delay block, too. So it is very easy to build. (Circuit / schematic design added 6/06)

A Weighting Filter for Audio Measurements: (Circuit / schematic design added 6/06)

Two Tone Audio Oscillator (use for SSB Tests): (added 7/02)

Two Tone Train Horn: (added 10/02)

Audio Level Control Device: compressor circuit based on LED and photodiode / (Electronic circuit added 7/03)

Digital Automatic Gain Control (Agc): (electronic circuit added 7/03)

OA-16: OA-16 Wideband AGC Amplifier as a Differential Amplifier: National Semiconductor Application Note (app note added 6/06)

Wideband AGC Amplifier as a Differential Amplifier: National Semiconductor Application Note 10-Apr-2000 (app note added 4/02)

Wideband AGC has 60 Db Dynamic Input Range: 10/10/96 EDN-Design Ideas / (added 4/02)

30 Ddm to +30 Ddm Audio Level Meter: circuit with balanced input and adjustable gain to drive needle type VU meter, uses special amplifier module from Op-Amp Labs (Circuit / schematic design added 6/06)

Audio Level Indicator: Audio Amplifier output relay delay (Circuit / schematic design added 6/06)

Audio Level Meter: (added 6/03)

Better Volume Control: how to create a log pot that is better than the "real" thing (Electronic Schematic / circuit added 4/02)

Digital Delay Unit for Surround Sound: (added 9/02)

Generating Tone using Pdo: Toshiba 870X Series Application Note (added 2/06)

Guitar Control: CaStand-alone, 9V battery powered unit . Three-level input selector, three-band tone control (circuit design added 3/05)

160 Baud ALDL Hardware Interface: This interface allows the vehicle's ALDL data stream to be displayed in real time on a PC using simple software. The hardware is designed to be able to be constructed by the average hobbyist who has a temperature controlled soldering iron and basic skills in constructing simple electronics. It uses a minimum of (readily available) components consistent with good electronics design. (Electronic circuit added 4/05)

6A door lock motor driver for automotive: AN456, put at low level the enable of the L9937, confirming the hardware switch-off of the motor ; in this condition an output of the half bridge is in... (app note added 6/06)

A solid state blinker for automotive applications: AN454 that limits the output current slew rate (di / dt) during the switching edges.... (Circuit / schematic design added 6/06)

AN10 Automotive Relay Drivers using the ZVN4206AV: Protection Free Interfacing with Avalanche Rated MOSFETs: Zetec Semiconductors - Applications Notes - An alternative solution is provided to the usual large package Darlington effected relay driver. The ZVN4206AV has been designed, processed and rated to withstand significant energy within the breakdown region. This allows the part to absorb back-emf and transient energy, thereby allowing lower component count circuits. (added 2/06)

AN-454: Automotive Multiplex Wiring: National Semiconductor - Application Note (app note added 2/06)

Automatic Dual Output Display: (Electronic Circuit / Schematic added 10/04)

Automotive protection with the rboxx series: AN555 See 4.1 : " Protection standards in automotive applications " for more details.... (app note added 6/06)

BMW R Series Motorcycle Regulator Schematic: (added 8/03)

2 Watt Amplifier #2: (diagram added 6/03)

3 Band Equalizer: (schematic / circuit design added 9/02)

3 Level Audio Power Indicator: Battery-operated Three LED display that connect it to loudspeaker output (added 6/06)

3 Tone Gong: Suitable for use as a door bell (added 6/06)

30 Ddm to +30 Ddm Audio Level Meter: circuit with balanced input and adjustable gain to drive needle type VU meter, uses special amplifier module from Op-Amp Labs (added 6/06)

300 Watt Subwoofer Power Amplifier: (electronic circuit added 7/03)

Active Subwoofer and Controller: (electronic circuit added 7/03)

AN543: Tone Generation: Microchip Application Note Published 26-Aug-97 (app note added 2/06)

Audio Graphic Equalizer: simple 7 band equalizer (added 4/02)

Audio Level Indicator #2: (circuit added 9/04)

Audio Level Indicator: Audio Amplifier output relay delay (added 6/06)

Audio level meter (VU Meter): This circuit uses just one IC and a very few number of external components. It displays audio level in terms of 10 LEDs. The input voltage can vary from 12V to 20V, but suggested voltage is 12V. The LM3915 is a monolithic integrated circuit that senses analog voltage levels and drives ten LEDs providing a logarithmic 3 dB/step analog display. LED current drive is regulated and programmable, eliminating need for current limiting resistors. The IC contains an adjustable voltage reference and an accurate ten-step voltage divider. The high-impedance input buffer accepts signals down to ground and up to within 1.5V of positive supply. Furr, it needs no protection against inputs of ±35V. The input buffer drives 10 individual comparators referenced to precision divider. Accuracy is typically better than 1 dB. (added 9/06)

Audio Level Meter: (diagram added 6/03)

Audio Tone Control: (circuit added 7/02)

Automatic Loudness Control: Simple add-on module Switchable "Control-flat" option (added 3/05)

Door Phone Intercom: (schematic / circuit design added 9/02)

Head Set Intercom : (diagram added 6/03)

IFB Intercom : (diagram added 6/03)

Intercom Schematic: (electronic circuit added 4/05)

Low Power Op Amp Audio Amp (Intercom): (circuit / schematic design added 6/06)

Old phones as an intercom (circuitsdb): From: mwandel@bnr.ca (Markus Wandel) I have recently thought about this and come up with a kludgy but workable scheme. Talking over the phones is easy. You put DC current through the phone and.... (added 2/07)

2 Line Output Combiner: Convert consumer equipment stereo signal to mono or combine audio signal from two different equipments to1-input (added 4/02)

Audio Signal Source: Electronic circuit design (added 02/05)

FET Audio Mixer: (circuit added 7/02)

Line Mixer #2: mix two line level sources to one-signal, includes separate volume controls for both signals, passive circuit (added 4/02)

Portable Mixer: High-quality modular design 9V Battery powered Very Low current drawing (added 9/04)

Stereo Mixer : Can mix four separate audio inputs to mono or stereo output signal (added 4/02)

Two Line Output Combiner: Convert consumer equipment stereo signal to mono or combine audio signal from two different equipments to1-input (added 4/02)

2W Amplifier: Amplifier operates in Class AB mode; single 470R preset resistor controls quiescent current flowing through BD139/140 complimentary output transistors. Adjustment here, is a trade-off between low distortion and low quiescent current. Typically, under quiescent conditions, standby current may be 15 mA rising to 150 mA with a 50 mV input signal. A simulated frequency response is ... (added 2/07)

20w Amplifier: (electronic circuit added 4/05)

20 Watt GaAs-FET Power on 2.3 GHz: (diagram added 6/03)

2 Watt Amplifier #1: (circuit added 9/04)

18 Watt Audio Amplifier: High Quality very simple unit. No need for a Preamplifier (added 9/04)

100 Watt Guitar Amplifier #2: (schematic / circuit design added 9/02)

1 Watt 2.3 GHz RF Amplifier using a MRF2001: (diagram added 6/03)

Audio PreAmplifier #1: (electronic circuit added 9/03)

Audio PreAmplifier #2: (schematic / circuit added 10/02)

Dynamic Microphone Preamp : Notice how the transistor bias current flows through the microphone. A similar circuit can be used with an 8 ohm speaker but in that case you would put it in place of the emitter resistor. (added 2/05)

FM Band PreAmplifier: (electronic circuit added 7/03)

AN-147: Low Cost IC Stereo Receiver: National Semiconductor Application Note (app note added 2/06)

AN-543 - Stereo FM Transmitter (DSP, 26,085 bytes): AN-543-StereoFMTransmitter-Analog Device Application Notes (app note added 10/06)

JT-MB D Passive Stereo Matrix for M S MIC Technique: (circuit / schematic design added 6/06)

Ms Stereo Microphone: (circuit / schematic design added 6/06)

Low Cost 1000 Watt 300 Volt RF Power Amplifier for 27.12MHz: Application Note Microsemi-formerly Advanced Power Technology APT9701 ( app note added 2/07)

Operating precautions for RF Amplifiers AN-60-008: Application Note MiniCircuits.com (app note added 6/06)

Simple and Inexpensive High-Efficiency Power Amplifier Using New Apt MOSFETs: Application Note Microsemi-formerly Advanced Power Technology APT9403 ( app note added 2/07)

+/-2.5V Current-to-Voltage Converters: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (app note added 6/06)

AN-1244: Photo-Diode Current-To-Voltage Converters: National Semiconductor - Application Note (app note added 6/06)

AN-772: A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 - Analog Devices Application Notes (app note added 2/06)

1Variable Regulated Power Supply: (circuit / schematic design added 6/06)

A Digitally Programmable Gain and Attenuation Amplifier Design: AN-137 Analog Devices App Notes (app note added 2/06)

AB-111: Single-Supply Wien Bridge Oscillator: AB-111 Analog Devices Application Notes (app note added 2/06) Wien Bridge Oscillators require only one op amp, important in battery-operation. This circuit operates from a single 9V battery.

Accurately Testing Op Amp Settling Times: AN-256 Analog Devices Application Notes (app note added 2/06)

AN-106: A Collection of Amp Applications: AN-106 Analog Devices App Notes (app note added 2/06) Examines Some of Numerous and Widely Used Applications of Operational Amplifier

48 Input×16 Output Crosspoint IC Eliminates the Need for Multiplexer Amps: 02/20/03 EDN-Design Ideas / (Electronic circuit design added 02/05) Crosspoint switches are ideal for use in video-security systems, which accept multiple camera inputs while providing playback and multiple loop-through to multiple monitors. To provide video loop-through or monitor outputs, these systems often require additional multiplexer amplifiers that can drive standard video loads...

LH0032 Video Amplifier: (Circuit / schematic design added 6/06)

LM359N Video Amplifier: (Circuit / schematic design added 6/06)

NTSC-to-VGA Scan Converter: This is a scan converter for NTSC signal from TV, VCR, LD or DVD to VGA conversion. Your VGA monitor will able to be used for video monitor. (Schematic / circuit added 10/05)

Video Amplifier: This is a Video amplifier that has been constructed by a single special IC LH0024. (Electronic Circuit diagram added 03/03)

Video Inverter: This is a simple one-transistor circuit to invert the whole video signal, including sync pulses. (Electronic Schematic / circuit added 4/02)

12 Bit ADC Upgrades µC's Internal 8 Bit ADC: Maxim Application Notes / 119 / Mar-03 (app note added 6/06)

12-Bit 3msps Sar ADC Solves Pipeline Problems: DN192 Design Notes (Linear Technology) (app note added 1/06)

16-Bit 333ksps ADC Achieves 90db Sinad,100db Thd and No Missing Codes: DN177 Design Notes (Linear Technology) (app note added 1/06)

16mw Serial/Parallel 14-Bit ADC Samples at 200ksps: DN180 Design Notes (Linear Technology) (app note added 1/06)

4 Channel 8 Bit Analog-to-Digital Converter for PC: (circuit added 7/02)

A 3-Phase Power Meter Based on the ADE7752: AN-641 Analog Devices Application Notes (app note added 2/06)

A Geophone/Hydrophone Acquisition Reference Design: AN-566 Analog Devices Application Notes (app note added 2/06) The AD1555/AD1556 24-Bit Sigma-Delta ADC Chipset Provides for Direct Acquisition of High Dynamic Range Sensors.

A Low Cost Watt-Hour Energy Meter Based on the ADE7757: AN-679 Analog Devices Application Notes (app note added 2/06)

Crystal Radio Circuits : (Schematic / circuit added 10/05)

LED Decibel Meter : (Schematic / circuit added 10/05)

Simple 3 Transistor Audio Amp (50 Milliwatt): (Schematic / circuit added 10/05)

Adding Additional Input Channels to the AD7773 & AD7775: AN-210 - Analog Devices Application Notes (app note added 2/06)

An Unbalanced Mute Circuit for Audio Mixing Channels: AN-127 - Analog Devices Application Notes (app note added 2/06)

AN-248: ADG201A/ADG202A and ADG221/ADG222 Performance with Reduced Power Supplies (pdf, 170,252 bytes): AN-248 - Analog Devices Application Notes (added 2/06)

AN-349: Keys to Longer Life for CMOS (pdf, 91,236 bytes): AN-349 - Analog Devices Application Notes (app note added 2/06) Here's How CMOS Can be Protected Against Abuse

AN-686: Implementing an I2C® Reset (pdf, 45,554 bytes): AN-686 - Analog Devices Application Notes (app note added 2/06)

Analog Switch Expands I 2 C Interface: 11/22/01 EDN Design Ideas / (added 12/04) Perhaps the most effective way to gain board space and increase component density is to minimize wiring on the board. A widely used architecture that allows such miniaturization is the I2C bus. Comprising only a bidirectional data line, SDA, and a clock line, SCL, this bus requires no chip selects or other additional connections. ...

Applying IC Sample and Hold Amplifiers: AN-270 - Analog Devices Application Notes (app note added 2/06)

16 Stage BiDirectional LED Sequencer: (circuit added 7/02)

18 Stage LED Sequencer: (circuit / schematic design added 6/06)

2 Transistor 2 LED Flasher: (circuit / schematic design added 6/06)

2 Transistor LED Flasher #1: (circuit added 7/02)

2 Transistor LED Flasher #2: (electronic design added 9/02)

2 Wire Lamp Flasher: Ideal to operate3 to24 Volt DC existing on-Circuit lamps LED operation is also possible (added 9/04)

220 Volts Flashing Lamps: Especially designed for Christmas tree lamps to replace old rmally-activated switches (added 9/04))

2-wire Lamp Flasher: This circuit has been designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert circuit between existing lamp and negative supply. Especially suited for car or panel pilot lights, this device can drive lamps up to 10W.... (design added 11/06)

3rd Brake Light Pulser: (electronic diagram added 6/03)

3 Xenon flashing circuits found in flash for disposable cameras: (electronic schematic

Bandpass Filter: This circuit is taken from the Progressive Communications Receiver in most of the recent ARRL Handbooks. Values for the 40 meter band are shown. (Electronic circuit design added 02/05)

Band-pass filters: (Electronic circuit design added 02/05)

Components of a simple bandpass filter: (Electronic circuit design added 02/05)

Notch Filter Is DC Accurate: 03/02/95 EDN Design Ideas / (circuit added 7/02) Most active filters exhibit noise, distortion, gain error, and dc offset. However, a filter topology that separates the dc and ac paths can eliminate the last two of these unwanted behaviors (Fig 1a). The dc path in this circuit has no op amps and, therefore, no dc offset. The dc path does not have a dc gain error other than -6 dB of attenuation that the R1/R2 divider causes. (This attenuation is absent if you omit the R2 termination.) The ac path consists of C1 and a synthetic inductor comprising two wideband transconductance amplifiers and associated components. The result is an active circuit that emulates the passive filter of Fig 1b...

Wideband Filter uses image Parameters: 10/26/00 EDN-Design Ideas / (added 05/03) / PDF contains multiple circuits - scroll to find this circuit

AN-D9: TN06 Series: Battery Back-Up Utilizes Low Threshold: Supertex Semiconductors (app note added 2/06)

Battery Backup Converter uses One NiCd Cell: 02/03/97 EDN Design Ideas / (Circuit / schematic design added 6/06) Notebook computers and other portable equipment often use a backup battery to retain memory contents during replacement of the main battery. Such "bridge batteries" usually consist of five or six series-connected NiCd coin cells. They're expected to keep the system alive for approximately 5 minutes—plenty of time to swap batteries. The circuit in Figure 1 reduces size, weight, and cost by using one NiCd cell instead of five or six. A Saft VB4E 40-mAhr NiCd coin cell has enough capacity to keep a typical notebook computer in suspend mode for approximately 10 minutes. All components (excluding the coin cell) consume less than 1/2 in.2 of pc-board area, and the cost savings from fewer cells help pay for the added circuitry.....

Buck Converter Handles Battery Backup System: 04/24/03 EDN Design Ideas / (added 12/04) A synchronous buck converter is inherently bidirectional. That is, it transfers energy from input to output as a buck regulator when the output voltage is low, but, when the output voltage is high, the converter acts as a boost regulator, transferring power from output to input. This Design Idea shows how to use this bidirectional energy transfer to automatically recharge a battery when the mai......

Memory Supply Includes Battery Backup: 02/03/97 EDN-Design Ideas / (Circuit / schematic design added 6/06)

Microcontroller Provides SrAM Battery Backup: 06/26/03 EDN Design Ideas / (added 12/04) To maintain content in the event of power loss, many designs that include SRAM require a dedicated device that can automatically switch from a standard power supply to battery operation. Microcontrollers seldom find use in power-switching applications. Because microcontrollers typically operate from the primary power supply, they stop execution if that supply drops, thereby making it impossible......

TN06 Series: Supertex Semiconductors (app note added 2/06)

Amplified Zener: A 13 volt Zener diode will work well for charging a 12 volt battery on Standby use. Or use a 14 volt zener a diode for a Standard 14.6 volt charge…. (circuit / schematic design added 10/06)

Battery Charger: Current and Voltage Regulated for Sealed Lead Acid types (electronic circuit added 10/06

Battery Discharge Monitor: (schematic / circuit added 10/02)

Battery Equal Charge Indicator: (circuit / schematic design added 6/06)

Broken Charger-Connection Alert: Detects if a device is not properly connected to its supply. Suitable for battery chargers, portable appliance supplies etc. (added 3/050

Charge Monitor for 12 Volt Rechargeable Lead Acid Battery: (electronic Circuit / Schematic added 10/04)

Motor Accu Lader: Electronic circuit (added 9/04)

Muscle power drives battery-free electronics: 11/21/05 EDN Design Ideas / (added 10/06) Your sweat and a super-cap replace the battery.

Picref-5: Smbus Level-3 Battery Charger/Selector Reference Design Based on the PIC16C73a: Microchip Application Note Published 11-May-98 (app note added 2/06)

Salt Water Battery: (electronic circuit added 10/05)

Solar Cell Battery Charger: (electronic circuit added 10/06)

Step Up supply charges battery while serving load : The circuit in Fig 1 supports portable applications in which a microprocessor controls battery charging. Step-up switching regulator IC1 boosts VIN (5V) to supply a combination of charging and load current. (Note that the 5V source must have short-circuit protection.) IC2 is a high-side current-sense amplifier that monitors charging current. Commands from the processor are CHARGE ON /OFF and FAST/TRICKLE CHARGE 06/08/95 EDN-Design Ideas / (added 11/05)

The Amplified Zener: A 13 volt Zener diode will work well for charging a 12 volt battery on Standby use. Or use a 14 volt zener a diode for a Standard 14.6 volt charge…. (circuit / schematic design added 10/06)

Zap Adapter: "Don't throw away those seemingly un-chargeable, rechargeable batteries; they could very well be brought back to life with the aid of this simple circuit." (circuit added 9/04)

12V Lead-Acid Battery Monitor: (electronic circuit added 4/05)

A Battery Powered Lap Top Computer Power Supply: DN18 Design Notes (Linear Technology) (app note added 2/06)

AB-32 / Battery Charger Applications: Fairchild Application Notes / (app note added 6/06)

AB-33 / Battery Charger Applications: Fairchild Application Notes / (app note added 6/06)

AB-34 / Battery Charger Applications: Fairchild Application Notes / (app note added 6/06)

AN-4138 / Design Considerations for Battery Charger Using Green Mode Fairchild Power Switch (FPStm): Fairchild Application Notes / (app note added 6/06)

Analog Circuit is Accurate Battery Fuel Gauge: Unpublished 10/98 Circuit acts as a fuel monitor for a rechargable battery, typically NiCd or NiMH chemistries. Analog type needle output meter appears like an automobile gas gauge. (added 9/04)

Automatic Power Off Circuit Saves Battery: 12/05/96 EDN-Design Ideas / (added 9/04)

Battery Characterizer: (Electronic circuit added 4/05)

Battery Simulator Provides Current Limiting : 08/01/97 EDN Design Ideas / (added 5/03) A constant-voltage active load can perform as a battery during the charge cycle. You can set the load voltage from 5 to 35V by using potentiometer PV and thus can simulate batteries ranging from 6 to 32V.

Constant Voltage Load Tests Battery Chargers: 04/11/96 EDN-Design Ideas / (added 6/06)

LED Battery Condition Indicator: (Electronic circuit added 4/05)

Phantom Power Battery Test Circuit: LED will light when battery is over42 volts (added 3/03)

Self-Powered Fast Battery-Tester: Tests 1.5 to 15 Volt cells. Two-LED display, no power supply required (added 3/05)

Simple car battery tester: This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every.... (added 2/07)

Test Batteries Without a Voltmeter Part 2: 03/15/01 EDN-Design Ideas / (added 11/05)

/ circuit added 05/07)

40 LED Bicycle Light (555 Timer 6 Volt): (circuit added 7/02)

8 Random Flashing LEDs: This project flashes eight LEDs in an apparently random manner. It uses a 4060 combined counter and display driver IC which is designed for driving 7-segment LED displays. The sequence is not really random because seven of LEDs would normally be display segments, eighth LED is driven by an output that is normally used for driving furr counters. The table below shows sequence for LEDs. You can use less than eight LEDs if you wish and table may help you decide which ones to use for your purpose. (added 09/05)

3 Input First Response Monitor: (circuit / schematic design added 6/06)

48kw Resonant Converter for X-Ray Machines Uses High Speed Power Modules With Integral Liquid Cooling: This paper describes an innovative method for the removal of heat from the four IGBT power modules equipping a 48kW ZVS-mode resonant power converter for CT X-ray machines. Application Note Microsemi APT9904 ( app note added 4/08)

An inexpensive x-ray machine: (electronic Circuit / Schematic added 10/04)

Automated Crib Lights: (circuit added 9/04)

Automated External Defibrillator: Intersil Application Block Diagram (app note added 6/06)

Blood Glucose Monitor: Intersil Application Block Diagram (app note added 6/06)

Brain Wave Machine: (electronic circuit added 7/03)

Breath Alcohol Tester Controlling a car ignition system: (electronic circuit added 4/05)

Cardiac Monitor: (electronic circuit added 7/03)

Cranial Electrotherapy Stimulator: Current generated flows through clips placed on the earlobes Output current adjustable from 80 to 600 MicroAmperes (added 9/04)

Digital Step Km Counter Max.: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (added 02/05)

EKG/EEG Circuit: (electronic circuit added 7/03)

Electronic Stethoscope (aaroncake): (circuit added 7/02)

Esp Sim (Sound Impairment Monitor): (electronic circuit added 4/05)

AN-1150: COP8 FLASH ISP HANDBOOK-Intro to ISP: National Semiconductor Application Note (app note added 2/06)

AN-1281:Bumped Die (Flip Chip) Packages: National Semiconductor Application Note (app note added 2/06)

CMOS Toggle Flip Flop using Laser Pointer: (circuit / schematic design added 6/06)

CMOS Toggle Flip Flop with Relay(Cd4013): (circuit added 7/02)

Discrete BiStable Flip Flop: (electronic (schematic / circuit added 4/02)

Discrete Set/Reset Flip Flop: (electronic (schematic / circuit added 4/02)

Flip Flop Flashers Buzzers Etc.: (electronic circuit added 7/03)

Follow the Debouncing Flip-Flops: 02/17/00 EDN-Design Ideas / (added 6/06)

High Current MOSFET Flip Flop with Debounced Pushbutton: (circuit / schematic design added 6/06)

Monostable Flip Flops (One Shot): (circuit added 7/02)

Set/Reset Flip Flop: (electronic design added 10/06)

Soft on/Off Switch: Modern electronic equipment incorporate "push-to-on-push-to-off" switches that do not make noise as with old equipment. An example of this is the power button on a ATX computer cabinet. Here is a circuit that does the same. It can be used to turn on/off any electronic/electrical equipment that operates on any range of voltages. When the "ON/OFF" button is.... (added 10/05)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package LFCSP: AN-772 Analog Devices Application Notes (app note added 2/06)

A User's Guide to I.C. Instrumentation Amplifiers: AN-244 Analog Devices Application Notes (app note added 2/06)

Active Feedback IC Serves as Current Sensing Instrumentation Amplifier: 07)/24/03 EDN Design Ideas / (added 12/04) High-speed current sensing presents a designer with some significant challenges. Most techniques for sensing current involve measuring differential voltage current produces as it flows through a sense element, such as a resistor or a Hall-effect device. The differential voltage across sense element is generally small and is often riding on a common-mode voltage that is considerably ......

AN-202: An IC Amplifier User’s Guide to Decoupling, Grounding, and Making Things Go Right for a Change: AN-202 Analog Devices Application Notes (app note added 2/06)

AN-245: Instrumentation Amplifiers Solve Unusual Design Problems: AN-245 Analog Devices Application Notes (app note added 2/06) Traditionally Considered Only for Transducer-Conditioning Applications, Instrumentation Amplifiers Bring Unique Performance Benefits to a Range of Or Applications as Well.

AN-306: Synchronous System Measures µΩs: AN-306 Analog Devices Application Notes (app note added 2/06) Synchronous Detection Scheme Measures Low Resistances

AN-320A: CMOS Multiplying DACs and Op Amps Combine to Build Programmable Gain Amplifier, Part 1: AN-320A Analog Devices Application Notes (app note added 2/06)

Bass-Treble Tone Control Circuit: The LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. An additional control input allows loudness compensation to be simply effected. Four control inputs provide control of bass, treble, balance and volume functions through application of DC voltages from a remote control system or, alternatively, from four potentiometers which may be biased from a Zener regulated supply provided on circuit. Each tone response is defined by a single capacitor chosen to give desired characteristic.….. (added 6/06)

Better Volume Control: how to create a log pot that is better than "real" thing (added 4/02)

Build a Simple Soft Action Muting Switch: 10/14/04 EDN-Design Ideas / (added 10/05) The circuit in Figure 1 adds a soft muting switch with power-up/power-down muting to a line-level audio circuit. R4, C1, and JFET Q1 quietly ground a signal in 100 to 200 msec when you close S1 or release it when you open S1. Potentiometer R2, set to twice Q1's cutoff voltage, makes on/off transition....

Designing with the LMC835 Digital Controlled Graphic Equalizer: National Semiconductor Application Note 04-Nov-1995 (app note added 4/02)

Digital Delay Unit for Surround Sound: (schematic / circuit design added 9/02)

Digital Volume Control has Log Taper: 04/11/02 EDN Design Ideas / (added 12/04) Digital potentiometers provide a compact and convenient way to attenuate audio-amplifier signals. However, most such potentiometers suffer from at least one flaw: a nonlogarithmic step increment. To avoid this problem, a user must usually step the potentiometer in a nonlinear sequence to simulate a logarithmic taper. ...

Digital Volume Control: based on DS1669 Digital Pot IC (added 5/02)

Dual Channel Digital Volume Control: (electronic Circuit / Schematic added 10/04)

Easy Parametric and Graphic Eq's Plus Peaks and Notches: (electronic circuit added 8/02)

Generating Tone using Pdo: Toshiba 870X Series Application Note (app note added 2/06)

Guitar Control: CaStand-alone, 9V battery powered unit . Three-level input selector, three-band tone control (added 3/05)

Test Batteries Without a Voltmeter: 11/09/00 EDN-Design Ideas / (added 5/02) / PDF contains multiple circuits - scroll to find the one of interest / This circuit an easy approach to testing batteries without exiting the voltmeter. The battery holders in sizes AAA, AA, C, and D make this tester so much faster than a voltmeter.

1-Wire Barometer: The circuit requires an additional power source other than that of the 1-Wire network. The MPX4115 requires about 7 ma of current. This is more than a 1-Wire network can provide without an elaborate circuit to store parasitic power from the 1-Wire network for short burst of current for pressure measurements. Two voltage regulators are used to provide both 5.0 and 10.0 voltages from a source of DC power ranging from 12 to 24 volts. (Circuit / schematic design added 6/06)

Basic Stamp Based Altimeter: A method of determining altitude is by the use of barometric pressure; however, it is not done without difficulty. The relationship of pressure vs. altitude is not a linear one, it is actually a fairly complex one, which the army came up with in the 1930's. This is the equation for calculating .... (Circuit / schematic design added 6/06)

Electronic Barometers: (Electronic circuit added 7/03)

Liquid Barometers: (Electronic circuit added 7/03)

One Wire Barometer: (Electronic Circuit added 03/06)

Portable Altimeter : Todd's Fascination with Flight. Read how Todd designed a portable altimeter using a micro-machined pressure transducer….. Gadget Freak / Design News (Schematic / circuit added 10/05)

Small Portable Altimeter Operates from a Single Cell: 06/21/01 EDN-Design Ideas / (added 5/03)

555 Tone Generator 8 Ohm Speaker: (circuit added 7/02)

AN16 Automotive and Household Siren Driver Circuits: Zsd100 and Discrete 'H'-Bridge Minimum Parts Count Solution: Zetec Semiconductors Applications Notes A solution is provided that uses a minimum number of components by utilising an application specific signal generation IC, and a high efficiency 'H'-bridge effected with 3A DC rated Super-δ TO92 style switching transistors. (app note added 2/06)

Audio MilliVoltmeter: (schematic / circuit design added 9/02)

Automotive and Household Siren Driver Circuits: Zsd100 and Discrete 'H'-Bridge Minimum Parts Count Solution: Zetec Semiconductors Applications Notes A solution is provided that uses a minimum number of components by utilising an application specific signal generation IC, and a high efficiency 'H'-bridge effected with 3A DC rated Super-δ TO92 style switching transistors. (app note added 2/06)

Beeper: This circuit produces sound of a beeper like one in pagers which produces a "beep-beep" sound. Basically circuit consists of a 555 timer oscillator which is turned ON and OFF periodically. The first C (left) oscillates at about 1Hz. The second IC is turned ON and OFF by first IC. The first IC determines how fast second IC is turned ON/OFF and second IC determines tone of final output. By varying VR1, changeover rate can be adjusted. By varying VR2 tone can be adjusted. If you know something about electronics, you can try replacing 2nd 555 IC circuit with a piezoelectric buzzer. This saves one IC and associated components but buzzer cannot give a loud sound as speaker and also its tone cannot be varied. (added 6/06)

Bells Ring Generator: 3-Circuit options Can be synchronized to Christmas tree flashing lights (added 9/04)

Birdie Doorbell Ringer: (electronic (schematic / circuit added 4/02)

Buzzer: (electronic circuit added 8/02)

Continuity Buzzer is Frugal with Power: 04/15/99 EDN-Design Ideas / (added 11/05) [Note: File contains multiple circuits. Scroll to find this one] The continuity detector in Figure 1 is based on W Dijkstra's "Fleapower circuit detects short circuits" (EDN, July 2, 1998, pg 122). The buzzer indicator allows you to devote full attention to making the connection without having to observe an LED. The circuit also consumes less power than Dijkstra's circuit. Power comes from two AA or AAA cells, which last for a period equal to their shelf life. Current consumption is less than 2.5 mA when the circuit detects continuity and less than 1.7 mA for an open circuit. Open-circuit voltage is less than 100 mV, and short-circuit current is less than 1 mA. You can use a number of op amps for IC1, provided that the specs indicate rail-to-rail operation with a low-voltage single supply....

Controller Provides Multiple Alarm Driver Formats: 01/15/98 EDN-Design Ideas / (added 08/05) DC/DC converters for use inside the telephone handset require operation from the high-source-impedance phone line. Additionally, the CCITT specifications call for maximum on-hook power consumption of 25 mA. The dc/dc converter in Figure 1 is 70%-efficient at an input power of 25 mA, providing 5V at 3.4 mA. Controlled, low-peak switch current ensures that the 48V input line experiences no excessive voltage drops during switching.

Cuckoo sound Generator: Agreeable, very close sound imitation Suitable for sound effects, door-bells etc. (added 9/04)

Curious C Beeper: (electronic circuit added 7/03)

Ding-Dong Bell: (electronic Circuit / Schematic added 10/04)

Doorbell for the Deaf: (electronic design added 10/06)

Doorbell with Counter: (electronic circuit added 1/03)

1.5 Volt LED Flashers #1: four circuits with description (added 4/02)

10 Channel LED Sequencer: based on4017 (added 4/02)

10 LED Sequencer: in PDF format, text in Finnish (added 4/02)

10 Stage Light Sequencer: flashes10 low voltage bulbs, operates at10-25-Volt voltage, in PDF format, text in Finnish (added 4/02)

12 Stage Neon Sequencer (NE 2/NE 51): uses small power 70-Volt neon bulbs (added 4/02)

12 Volt Strobe Circuit: this circuit uses12V DC instead od mains AC. This is very good idea if you don't want to mess with direct mains voltage connected circuit or you want to run Strobe from batteries. (added 4/02)

120 VAC Lamp Chaser using Solid State Relays: (circuit / schematic design added 6/06)

120 Volt AC Lamp Chaser using Solid State Relays: This circuit is similar to LED clock using12 neon indicator lamps instead of LEDs. It operates from2 high capacity ni-cad cells (2.5 volts) which keep it going for a couple weeks. High voltage (70 volts) for neon lamps is obtained from a small switching power supply using a 74HC14 Schmitt trigger Squarewave oscillator, high voltage switching transistor, and10 mH high Q inductor. Most any small PNP transistors can be used that have a C/E voltage rating of 80 or more. (added 4/02)

Sound Controlled Flip Flop: Described here is a very inexpensive solution to many phono-controlled applications like remote switching on, for instance, or activating a camera, tape recorder, burglar alarms, toys, etc. The circuit given here employs a condenser microphone as the pick-up. A two-stage amplifier built around a quad op-amp IC LM324 offers a good gain to enable sound pick-up upto four metres. …. (added 10/05)

Spare flip flop stretches WR strobe for DSP: 07/20/95 EDN-Design Ideas / (added 2/06)

Spare gates form edge triggered flip flop: 03/16/95 EDN-Design Ideas / (added 2/06)

Telephone Line Based Audio Muting and Light on Circuit: (added 4/02)

Telephone Line Based Audio Muting and Light-On Circuit: (electronic Circuit / Schematic added 10/04)

Verilog Program Models metastable flip flop: 05/12/94 EDN Design Ideas / (added 11/05)

0.6/1.6 MHz Boost Converters with 22V Inrternal FET Wsitch in SOT-32: National Semiconductor Application Note LM2731 July 2003 (app note added 7/06)

1 Watt 5 Volts Power Booster for the MLX90121: Melexis Application Note (app note added 2/06)

2-Phase Boost Converter Delivers 10W from a 3mm x 3mm DNF Package: DN354 - Design Notes (Linear Technology) (app note added 1/06)

2-Transistor Amplifier: A simple two-stage Amplifier. Use any general-purpose NPN with high gain. It will drive low impedance headphones directly. A speaker will probably require further boost. (added 10/05)

3 Output TFT LCD Bias Supply with a Boost Regulator - MP1542 - DN0005: Monolithic Power Systems, Inc - Design Note - (added 6/06)

3.3V converter delivers 3W from Li-ION battery : 11/05/98 EDN-Design Ideas / (added 11/05) Lithium-ion batteries are rapidly gaining popularity in portable applications because of their superior energy density, low self-discharge rate, and high cell voltage. When you use one Li-ion battery to power a 3.3V dc/dc converter; however, you encounter a problem, because the battery voltage can be higher or lower than 3.3V. When fully charged, a Li-ion cell has approximately 4.2V output; when fully discharged, the voltage is approximately 2.5V. Therefore, you cannot use a simple buck or boost topology with a single inductor to generate a regulated 3.3V output. Some designs boost the voltage to approximately 4.3V and then use a low-dropout regulator to produce the 3.3V. This approach is inefficient, and efficiency is a crucial consideration in battery-powered applications. The circuit in Figure 1 offers a solution to the problem....

3-Band Equalizer: Using a single op-amp this easy to make equalizer offers three ranges, low frequency, mid frequency, and high. With component values shown there is approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz. Supply voltage may be anything from 6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage. (added 4/05)

3MHz Micropower Synchronous Boost Converters Deliver 3W from Two Cells in a Tiny MSOP Package: DN246 - Design Notes (Linear Technology) (app note added 2/06)

4-Phase Monolithic Synchronous Boost Converter Delivers 2.5A with Output Disconnect in a 5mm x 5mm QFN Package: DN332 - Design Notes (Linear Technology) (app note added 2/06)

500kHz 6monolithic Boost Converter (LT1370): DN183 - Design Notes (Linear Technology) (app note added 1/06)

A 500kHz 6a Monolithic Boost Converter (LT1370): DN183 - Design Notes (Linear Technology) (app note added 6/06)

A Power Booster for the MLX90121: Melexis Application Note (app note added 2/06)

A Step-Down Conversion Concept for a Pwm-Mode Boost Converter: TI Application Note (added 2/06)

Add Current Boost to a USB Charger: 09/19/02 EDN Design Ideas / (added 1/05) The popular USB interface can charge a portable device while transferring data. But for high-capacity batteries, the 500-mA output current of USB hosts and powered hubs greatly extends the charging time. (Unpowered USB hubs supply no more than 100 mA.) Thus, a system that accepts charging power from an ac adapter as well as the USB port is more convenient....

AN-1066: Low Cost Boost Converters using LM3578A: National Semiconductor - Application Note (app note added 2/06)

AN-1221: LM2623 General Purpose, Boost Converter Circuit: National Semiconductor - Application Note (app note added 7/06)

AN-1235: Using Smart Charge Sharing to Reduce Power and Boost Column Driver Performance: National Semiconductor - Application Note (app note added 7/06)

AN-1258: National's LM2623 Boost Converter: A Simple Supply: National Semiconductor - Application Note (app note added 2/06)

AN-1286: Compensation for the LM3478 Boost Controller: National Semiconductor - Application Note (app note added 7/06)

AN-1362: LM27961-Dual-Display White LED Driver with 3/2x Switched Capacitor Boost: National Semiconductor - Application Note (app note added 2/06)

AN-272: Op Amp Booster Designs: National Semiconductor - Application Note (app note added 2/06)

AN34 ZXSC100 Power Supply for Digital Still Camera: Zetec Semiconductors - Applications Notes - A basic guide to the DC-DC Converter requirement and concept, including an introduction to the Zetex enhanced TO92 - the E-Line package, and some suggested applications where these components offer advantages. (app note added 7/06)

AN980: Designing a Boost-Switching Regulator with the MCP1650: Microchip Application Note - Published 1-Apr-05 (app note added 2/06)

App Note 14 - Power Booster Applications: Apex Microtechnology Corp - App Note - (added 6/06)

Application for a New Power Buffer: AN4 - Linear Technology - The LT1010 150mA power buffer is described in a number of useful applications such as boosted op amp, a feed-forward, wideband DC stabilized buffer, a video line driver amplifier, a fast sample-hold with hold step compensation, an overload protected motor speed controller, and a piezoelectric fan servo. (app note added 7/06)

Battery Booster Delivers 75W: 07/16/98 EDN Design Ideas / (added 07/02) The circuit in Figure 1 defies no laws of physics; it just makes creative use of an isolated dc/dc converter. The application uses the isolated converter in a nonisolated configuration to boost a 48V battery voltage to 60V. The PT3102 is a 15W isolated dc/dc converter that normally uses a 36 to 75V (48V-nominal) input voltage to provide a floating, or isolated, 12V output capable of 1.25A. The trick is to connect the negative-output lead and positive-input lead of the converter, thereby effectively stacking the 12V output on top of the 48V input. (Be aware that the original isolation and safety properties of the converter no longer exist in this configuration.)....

Bipolar Transistor Boosts Switcher's Current by 12 times: 05/24/01 EDN-Design Ideas / (added 8/03)

Boost 33V to 5V with Tiny Audio Amplifier: 09/05/02 EDN Design Ideas / (added 12/04) This charge-pump circuit quietly converts a 3.3V source to 5V at 500 mA (figures 1 and 2). National's (www.national.com) LM4871LD power amplifier makes this design idea both possible and practical, thanks to its low output resistance, low cost, compact size, and high dissipation capability. Its output resistance has an average value of 0....

Boost Controller Drives Buck Converter: 02/03/97 EDN Design Ideas / (added 3/05) -- By adding an external Switching Transistor, you can use a step up dc/dc Converter to step down voltages to produce an efficient Battery Powered Power Supply, this example Circuit can step down inputs as Low as2V to Outputs as Low as1.25V, with efficiency as high as 80%

Boost Converter Controls 12 Volt Fan from 5 Volt Supply: 12/12/97 EDN-Design Ideas / (added 3/03) --Temperature-controlled PWM boost converter allows operation of a12V brushless dc fan from a5V supply

Boost Converter Generates 27 and 87V: 05/22/97 EDN-Design Ideas / (added 3/03) -- Generates the voltage levels necessary for standard telephones from12V

Boost Converter Generates Three Analog Rails #2: 07/02/98 EDN-Design Ideas / (added 3/03) The standard boost converter in Figure 1 uses not only IC1, C1, L1, D1, and C2 to generate a main 5V output, but also additional small, low-cost components to provide two auxiliary supply rails of 10 and -5V. These auxiliary outputs are useful for analog circuitry in small handheld instruments, which often require supply voltages greater than the signal range. Input voltages of 0.8 to 5.5V, which is equivalent to voltages from a battery pack of one to three cells, sustain the main regulated output of 5V±2%. With an input of 1.8V from two flat cells, for instance, and with the other rails unloaded, the circuit can produce 25 mA with 80 to 90% efficiency.

Boost Converter Generates Three Analog Rails: Maxim Application Note #2026 (app note added 7/03) In Figure 1, a standard boost converter consisting of IC1, C1, L1, D1, and C2 generates, in addition to the main output, two auxiliary supply rails (10V and -5V) with the addition of some small and very low-cost extra components. Such rails are useful for the analog circuitry in small handheld instruments, which often require supply voltages in excess of the signal range....

Boost Converter Works with Wide Range Negative Input Supply: 03/18/04 EDN Design Ideas / (added 1/05) Assume that a design requires positive voltage, but only a negative-voltage power source is available. Using a standard boost-converter IC in the circuit of Figure 1, you can efficiently generate a positive voltage from a negative source. The boost converter generates an output voltage that's higher than the input voltage....

Boost Reference Design: This design uses the UCC38C43 as a boost power supply controller. It operates from a 12 volt input and generates a 24 volts (or higher) output voltage. The input voltage can be widely varying as the UCC38C43 can sustain a 20 volt maximum input. (added 3/05)

Boost Regulator Makes Low Profile SEPIC with Both Step-Up and Step-Down Capability: DN317 - Design Notes (Linear Technology) (app note added 2/06)

Boosting Regulator Current: Although the 78xx series of voltage regulators are available with different current outputs, you can boost the available current output with this circuit. A power transistor is used to supply extra current to the load the regulator, maintaining a constant voltage. Currents up to 650mA will flow through the regulator, above this value and the power transistor will start to conduct, supplying the extra current to the load. This should be on an adequate heat sink as it is likely to get rather hot. Suppose you use a 12v regulator, 7812. The input voltage should be a few volts higher to allow for voltage drops. Assume 20 volts. Lets also assume that the load will draw 5amps. The power dissipation in the transistor will be Vce * Ic or (20-12)*8=40watt. It may keep you warm in the Winter, but you will need a large heatsink with good thermal dissipation. If you want to increase the output current with a negative regulator, such as the 79xx series, then the circuit is similar, but an NPN type power transistor is used instead. (added 7/06)

Bootstrapped Boost Converter operates at 1.8 Volt : 04/23/98 EDN-Design Ideas / (added 05/03)

Bootstrapped Timer: This circuit demonstrates how to use bootstrapping to seriously boost the output power of the timer. The LC555 can only put out about 50mA as it is. This circuit can put out at least 200mA and goes to the rail as well. The LM555 timer puts out 300mA max, but doesn’t go all the way to the rail. Replace Q1 with a big MOSFET, and you can put out big current with these few components. Designed by Andrew R. Morris (added 09/05)

Buck IC Boosts Battery Voltage for White LED: 04/24/03 EDN Design Ideas / (added 1/05) White-light LEDs are finding their way into many markets that incandescent bulbs once served. Flashlights are among the newer applications in which reliability, ruggedness, and ability to control the power draw of the LEDs make these devices attractive. With incandescent bulbs, the power management for the device is a simple on-off switch....

Buck or Boost: Rugged Fast 60V Synchronous Controller Does Both: DN370 - Design Notes (Linear Technology) (app note added 1/06)

Build a Charge Pump with UltraLow Quiescent Current: 09/05/04 EDN Design Ideas / (added 1/05) Portable battery-powered devices often spend most of their life in standby mode, in which the quiescent current of an internal boost converter continuously bleeds the battery. The quiescent current during standby can be larger than the actual load current. Though several inductor-based converters offer maximum quiescent current of less than 10 µA, designers usually prefer or require a regu......

Cascode MOSFET Increases Boost Regulator's Input and Output Voltage Ranges: 09/1/05 EDN -- Design Ideas / (added 6/06) Simple enhancement extends range of both sides of regulator.

Charge Pump and Step Up DC DC Converter Solutions for Powering White LEDs in Series or Parallel Connections: Maxim Application Note #1037 (app note added 7/03)

Circuit breaker handles Voltages to 32V: 05/25/00 EDN-Design Ideas / (added 2/06) The simplicity of low-side current monitoring can mask the advantages of a high-side approach. You can monitor load currents in a power supply, a motor driver, or another power circuit on either the high or the low side (ground). However, don't let the ease of low-side monitoring cause you to overlook its dangers or the advantages of a high-side approach. Various fault conditions can bypass the low-side monitor, thereby subjecting the load to dangerous and undetected stresses. On the other hand, a high-side monitor connected directly to the power source can detect any downstream failure and trigger the appropriate corrective action. Traditionally, such monitors required a precision op amp, a boost power supply to accommodate the op amp's limited common-mode range, and a handful of precision resistors. Now, the MAX4172 IC can sense high-side currents in the presence of common-mode...

Coilless Step Up Converter yields Dual Outputs: 09/01/97 EDN-Design Ideas / (added 3/03)

Compact Inductorless Boost Circuit Regulates White LED Bias Current: Maxim Application Note #1116 (app note added 7/03)

Compact Step-Up Converter Conserves Battery Power: DN358 - Design Notes (Linear Technology) (app note added 6/06)

Compensation for the LM3478 Boost Controller: National Semiconductor - Application Note (app note added 7/06)

Configure buck converter for boost operation : 12/17/98 EDN-Design Ideas / (added 2/06) Buck converters are inherently different from boost converters, because buck converters typically use the high side of the output as the power switch’s reference. However, a buck converter with a floating output drive section is configurable as a boost controller (Figure 1). This circuit configures the SC1101 buck controller for a 5 to ±12V boost with ±500 mA of output current. The BST pin, which normally connects to a high-side drive supply in a buck converter, connects to VCC to drive the ground-referenced MOSFET. By tying PGND to circuit ground, the SC1101 becomes a boost controller, yielding 12V from 5V. An output charge-pump voltage inverter provides –12V at 0.5A as well....

Controller IC and One Shot Form Resonant Controller: 11/28/02 EDN Design Ideas / (added 1/05) Resonant power supplies are popular because of high efficiency, low noise, and compactness. You can implement a resonant buck or boost converter using a single switch. The regulation of the output in such a converter derives from using a constant on or off time and a variable frequency. The UC1864 controller IC (Texas Instruments, www....

Cutting-Edge Mount Down Methods Boost Power Semiconductor Performance: This paper will evaluate the performance of TO-264 and new T-MAX™ plastic packaged MOSFETs in a variety of mount down situations, both galvanically isolated and electrically hot. Application Note Microsemi-formerly Advanced Power Technology APT9902 (app note added 4/08)

Designing a Boost-Switching Regulator with the MCP1650: Microchip Application Note - Published 1-Apr-05 (app note added 2/06)

DN0006 - MP1542 - SEPIC with Both Step-Up and Step-Down Capabilities : Monolithic Power Systems, Inc - Design Note - (added 6/06)

Dual-Display with LED Driver with 3/2x Switched Capacitor Boost: National Semiconductor Application Note LM2796 February 2004 (app note added 7/06)

EPLD configures wait-state generator : 02/03/97 EDN Design Ideas / (added 2/06) Using a faster microcontroller or microprocessor in an existing application can boost the performance of a system. Unfortunately, interfacing the faster processor to the much slower existing peripheral ICs is a complex task. To overcome this problem, new processors, such as Philips XA, have an external wait-state-insertion capability. Given this wait-state feature, the tricky part is to generate the wait-state signal itself. In many cases, you can use one-shot ICs, such as the 74HCT221. Unfortunately, these ICs have a slow response time. This Design Idea shows how to build a wait-state generator with a fast response time (5 nsec, typically) using an EPLD. A benefit of using an EPLD is that you can integrate other glue logic, such as address decoding, into the EPLD....

Gate Boost Solar Engine: Voltage-Controlled Solar Engine: The "Gate Boost Solar Engine" is a new (6/2002) Wilf Rigter 1381-based design. This uses an internal voltage doubler to turn on a FET more efficiently. (added 11/05)

Get Just Enough Boost Voltage: 05/27/04 EDN Design Ideas / (added 11/05) Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltage and to ensure a constant difference between the input and the output voltages (Figure 1). This circuit is useful for high-side-drive applications, in which a simple voltage doubler is unacceptable because of the voltage range of the components involved or where the input voltage can vary ...

Get more Power with a Boosted triode #1: 04/03/03 EDN-Design Ideas / (added 02/05) Even though 6L6 beam-power tubes have been around for 66 years, they are still quite popular for use in electric-guitar amplifiers, and its cousin, the 6CA7 (EL34) power pentode, is a favorite among audiophiles. The developers of these tubes designed them for pentode-mode operation, and they deliver maximum audio power in this mode...

Get more Power with a Boosted triode #2: 06/12/03 EDN Design Ideas / (added 02/05) This Design Idea is a reprint of an earlier one that contained errors in graphics (Reference 1). Even though 6L6 beam-power tubes have been around for 66 years, they are still quite popular for use in electric-guitar amplifiers, and its cousin, the 6CA7 (EL34) power pentode, is a favorite among audiophiles....

High Efficiency 2-Phase Boost Converter Minimizes Input and Output Current Ripple: DN371 - Design Notes (Linear Technology) (app note added 1/06)

High Voltage Amplifier uses simplified circuit: 10/14/04 EDN Design Ideas / (added 5/05) Many scientific instruments and sensors need ac high-voltage drive. High-voltage drive is useful for driving electrodes in many applications. The challenge is to boost the output of a conventional op amp to high voltages. Available ac high-voltage amplifier modules are limited to approximately 1200V p-p.

Using Smart Charge Sharing to Reduce Power and Boost Column Driver Performance: National Semiconductor - Application Note (app note added 7/06)

AN251: Bridge Sensing with the MCP6S2X PGAs: Microchip Application Note - Published 6-May-03 (added 2/06)

AN717: Building a 10-Bit Bridge Sensing Circuit using the PIC16C6XX and MCP601Operational Amplifier: Microchip Application Note - Published 3-Apr-01 (added 2/06)

App Note 3 - Bridge Circuit Drives: Apex Microtechnology Corp - App Note - (added 2/06)

Bridge Sensing with the MCP6S2X PGAs: Microchip Application Note - Published 6-May-03 (added 2/06)

Bridging Adapter for Power Amplifiers: (added 9/02)

Bridging enhances filter close-in selectivity: 03/02/00 EDN-Design Ideas / (added 2/06) General filters are bandpass filters that usually employ bridging couplings between nonadjacent interstage couplings (Reference 1). This class of filters also includes bridging coupling across the filter input and output ports. The implementation of input-to-output bridging already exists for a one-pole filter (Reference 2). For a two-pole filter, dielectric resonators help achieve input-to-output bridging coupling (Reference 3)....

Bridging Line Amplifier : (Circuit / schematic design added 6/06)

Building a 10-Bit Bridge Sensing Circuit using the PIC16C6XX and MCP601Operational Amplifier: Microchip Application Note - Published 3-Apr-01 (added 2/06)

Circuit Adds Programmability to Sensor Amplifier: 03/21/02 EDN Design Ideas / (added 12/04) The pressure-sensor amplifier circuit of Figure 1 offers a number of advantages over the traditional approach using the classic three-op-amp instrumentation amplifier. The circuit can operate from a single supply and uses only two op amps and 1% resistors. If the reference voltage, VREF, is 0V, the transducer gain for the circuit isTo ensure equal gain for the two ground-referenced volt... ...

Delta Sigma ADC Bridge Measurement Techniques: AN96 - Linear Technology - AN96 features several applications that demonstrate how to take full advantage of Linear Technology's delta sigma ADCs when interfacing to sensors. In many cases, signal conditioning can be greatly simplified or eliminated completely. This note explains where it is appropriate to use amplifiers and how to optimize amplifier gain. Also included are discussions on measuring effective number of bits (ENOB) and the relationship to instrument performance, frequency response of delta sigma ADCs, and test techniques. C source code for all of the applications is included to aid firmware development. (Circuit / schematic design added 6/06)

Design Approach Simplifies Signal Conditioning: 12/22/1994 EDN Design Ideas / (Electronic circuit added 5/02)

PIC16F84 TRIAC/IGBT Brightness Phase Controller: (Circuit / schematic design added 6/06)

Programmable Gain Amplifier is Low Cost: 03/17/1994 EDN Design Ideas / (Electronic circuit added 5/02) A programmable reference diode, such as the Motorola TL431A, can supply constant-current bias for a silicon pressure-sensor bridge (Fig 1). This circuit is simpler than using an op amp and separate reference diode or than using a current diode, which requires temperature compensation. The TL431A produces a VREF of 2.5V over a current range of 1 to 100 mA. The value of VREF/R2 sets the necessary bias current for the bridge sensor, as specified by the sensor manufacturer. The reference diode current, set....

Rc Network Eliminates Precision Reference: 08/04/94 EDN Design Ideas / (Electronic circuit added 5/02) The circuit in Fig 1 uses a magneto-resistive sensor to detect small magnet displacements without resorting to a precision voltage reference. A simple RC divider takes the place of the reference, eliminating an expensive component and obviating trimming each circuit....

Signal Chopping Enhances Bridge Performance: 06/22/95 EDN Design Ideas / (Electronic circuit added 5/02)

750 MHz Power Doubler and Push-Pull CATV Hybird Modules Using Gallium Arsenide (3/21/96) : Application Note California Eastern Laboratories Doc #920 (app note added 2/06)

A 50 Mhz, 250w Amplifier Using Push-Pull Arf448a/B: Application Note formerly Advanved Power Technology APT9702A (app note added 2/07)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 2/06)

A Push-Pull 300-watt Amplifier for 81.36 MHz: Application Note Microsemi-formerly Advanced Power Technology APT9801 (app note added 1/07)

An Introduction to IBIS (I/O Buffer Information Specification) Modeling: National Semiconductor Application Note (app note added 2/06)

AN-1111: An Introduction to Ibis (I/O Buffer Information Specification) Modeling: National Semiconductor Application Note (app note added 3/06)

AN-253: Find Op Amp Noise with Spreadsheet: AN-253 Analog Devices Application Notes (app note added 2/06)

AN-257: Careful Design Tames High Speed Op Amps: AN-257 Analog Devices Application Notes (app note added 2/06)

AN-329: Implementing an 8-Bit Buffer in COPS: National Semiconductor Application Note (app note added 2/06)

AN-345: Grounding for Low-and-High-Frequency Circuits: AN-345 Analog Devices Application Notes (app note added 2/06)

AN-349: Keys to Longer Life for CMOS: AN-349 Analog Devices Application Notes (app note added 2/06) Here's How CMOS Can be Protected Against Abuse

AN-356: User's Guide to Applying and Measuring Operational Amplifier Specifications: AN-356 Analog Devices Application Notes (app note added 2/06)

AN-359: Settling Time of Operational Amplifiers: AN-359 Analog Devices Application Notes (app note added 2/06)

AN-581: Biasing and Decoupling Op Amps in Single Supply Applications: AN-581 Analog Devices Application Notes (app note added 2/06)

AN-649: Using the Analog Devices Active Filter Design Tool: AN-649 Analog Devices Application Notes (app note added 2/06)

AN-692: Universal Precision Op Amp Evaluation Board: AN-692 Analog Devices Application Notes (app note added 2/06)

AN-772: A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 2/06)

AN-1222: AN-1222 Usbn9603/4: Increased Data Transfer Rate using Ping-Pong Buffering: National Semiconductor Application Note (app note added 2/06)

Applications of Wide-Band Buffer Amplifiers: National Semiconductor Application Note (app note added 2/06)

AN-253: Find Op Amp Noise with Spreadsheet: AN-253 Analog Devices Application Notes (app note added 2/06)

3 Transistor FM Radio Bug: (electronic Circuit / Schematic added 10/04)

Bug Detector #1: (electronic circuit added 7/03)

Bug Detector with Beep: (electronic circuit added 7/03)

FM Radio Telephone Bug: (circuit / schematic design added 6/06)

FM Transmitter Bug: (circuit / schematic design added 6/06)

High Power FM Microphone (FM Bug): (electronic Circuit / Schematic added 10/04)

Miniature FM Spy Mic: This spy mic works from single 1.5 volts AA type battery cell. It is highly sensitive and has a range of 300 meters. You can use any HF transistor with cut-off freq. >300 MHz for Q. Use electret mic. (added 6/06)

Phone Tap: (electronic circuit added 7/03)

Improved Kelvin contacts boost Current sensing accuracy by an order of magnitude: 02/17/05 EDN Design Ideas / (added 5/05) Many power-supply designs rely on accurately sensing the voltage across a current-sense element. Multiphase regulators use the sense voltage to force current sharing among phases, and single-phase regulators to control the current-limit setpoint. As internal complexity and clock speeds increase, processors impose narrower operating margins for power-supply voltages and currents, which in turn m...

Improved Power MOSFETs Boost Efficiency In A 35kw Single Phase Pfc: This paper charts the technological evolution of APT’s powerMOSFETs from the earliest PowerMOS IV designs to the latest PowerMOS 7TM products. The improvement in performance of a 3.5kW boost converter equipped in turn with different generation products is evaluated, as well as the influence of various MOSFET package styles on thermal behaviour and potentially harmful overvoltages. Application Note Microsemi APT0101 ( app note added 4/08)

Inductorless Switching Regulator Boosts Input Voltage: Maxim Application Note #5 (app note added 7/03)

Inductorless Voltage Converter Boosts a Single Lithium Cell: Maxim Application Note #1791 (app note added 6/06)

LED Boost Switcher: Single AA Cell Powers Two LEDs at Constant Current : (added 2/05)

LED Headlamps : This article includes circuits of DC-DC LED drivers step downs to run LEDs on less than Battery Volts, Boost for above. (added 4/02)

Linear Technology Magazine Circuit Collection Volume IV: AN84 - Linear Technology - Application Note 84 is a collection of "power circuits" from the years 1996 through 1998 as seen in the pages of Linear Technology magazine. This Application Note collects circuits that can output tens of amps to circuits that can operate a handheld device for several years. In addition to a wide variety of traditional power supply circuits (Buck, Boost, Inverting, Flyback, Linear Regulators, etc.) we include circuits for charging batteries, several Power Management circuits as well as circuits that highlight a very low noise switching regulator.

LM2623 General Purpose, Boost Converter Circuit: National Semiconductor - Application Note (app note added 7/06)

Low Cost Boost Converters using LM3578A: National Semiconductor - Application Note (app note added 2/06)

Low cost feedback circuit Boosts efficiency: 01/21/99 EDN-Design Ideas / (added 11/05) To implement a step-up converter with a current output, designers often simply connect the load in place of the top resistor in a resistive-divider feedback network. The bottom resistor then serves as a current-sense resistor. Though simple, this approach is inefficient. Low efficiency results from the relatively high sense voltages—usually, 1.25V but as high as 2.5V for some ICs. A switch-mode dc/dc converter configured as a 20-mA current source minimizes the efficiency loss by lowering the sense voltage to 200 mV (Figure 1). Advantages of this circuit include the factor-of-six gain in efficiency; minimal board area; and readily available, low-cost components. Applications include battery charging, LED drive, and general-purpose current sources....

Low Cost Switcher Converts 5 to 24V: 02/16/98 EDN-Design Ideas / (added 3/03) -- Low-cost, three-transistor low power boost switching regulator

Low Noise Step Up Supply Generates 5.5 Volt Output: 10/09/97 EDN-Design Ideas / (added 3/03)

LT1070 Design Manual: AN19 - Linear Technology - This design manual is an extensive discussion of all standard switching configurations for the LT1070; including buck, boost, flyback, forward, inverting and "Cuk." The manual includes comprehensive information on the LT1070, the external components used with it, and complete formulas for calculating component values.

LT1074/LT1076 Design Manual: AN44 - Linear Technology - This note discusses the use of the LT1074 and LT1076 high efficiency switching regulators. These regulators are specifically designed for ease of use. This application note is intended to eliminate the most common errors that customers make when using switching regulators as well as offering insight into the inner workings of switching designs. There is an entirely new treatment of inductor design based upon simple mathematical formulas that yield direct results. There are extensive tutorial sections devoted to the care and feeding of the Positive Step- Down (Buck) Converter, the Tapped Inductor Buck Converter, the Positive-to-Negative Converter and the Negative Boost Converter. Additionally, many troubleshooting hints are included as well as oscilloscope techniques, soft-start architectures, and micropower shutdown and EMI suppression methods.

LT1339 Design Manual: AN73 - Linear Technology - This application note contains detailed design information to allow the reader to craft switching regulators using the LT1339 high power synchronous DC/DC converter. The note provides expanded pin descriptions for the LT1339 as well as easy-to-use graphical tools for the design of high power synchronous buck and boost converters. The manual includes extensive information on the LT1339 and the external components used with it along with formulas and/or graphics to calculate component values.

LT1370: A 500kHz 6a Monolithic Boost Converter: DN183 - Design Notes (Linear Technology) (app note added 6/06)

LT1619: Tiny Boost Controller Provides Efficient Solutions for Low Voltage Inputs: DN255 - Design Notes (Linear Technology) (app note added 1/06)

LTC1871 No Rsense Controller is Small and Efficient in Boost Flyback and Sepic Applications: DN296 - Design Notes (Linear Technology) (app note added 1/06)

LX1741/LX1742 Boost Converter Design Hint (See Also DN-099A and DN-099B)-(AN-22): Application Note 22 from Microsem (app note added 6/06)

Op Amp Booster Designs: National Semiconductor - Application Note (app note added 2/06)

Palmpilot Turbo Boost Guage Interface: (Electronic circuit added 4/05)

Pass Transistor Lowers Dropout Voltage: 02/18/99 EDN-Design Ideas / (added 6/03) With linear regulators,you measure dropout voltage, VIN–VOUT, at the minimum input voltage for which the IC sustains regulation. Low dropout means longer battery life, because the load circuit continues to operate while the battery discharges to a lower terminal voltage. The external transistor helps to form a linear-regulator circuit whose dropout voltage at 100-mA load current is only 10 mV (Figure 1). (The linear-regulator IC by itself specs a 100-mV dropout at 100 mA.) The external transistor also boosts the maximum available load current to 1A....

Photo-flash charger minimizes parts count : 10/22/98 EDN-Design Ideas / (added 2/06) Photo-flash and strobe devices operate by discharging a high-voltage capacitor into a bulb. Charging the capacitor from a battery or other low-voltage source requires a step-up dc/dc converter to boost the voltage, typically to 300V. One way to generate the high voltage is to use a flyback converter. The circuit in Figure 1 provides a simple and reliable way to charge a high-voltage capacitor. The flyback converter performs two functions: It boosts the low-voltage input and provides isolation between the input (battery) and output (high voltage). Its main components are the power transformer; the output diode; the output capacitor; and the MIC3172 controller chip, which combines the switching transistor, voltage regulator, and control logic....

Positive regulator makes dual negative output converter: 06/26/03 EDN Design Ideas / (added 1/05) Some systems, such as optical networks, require more than one negative voltage. A common procedure is to boost the main negative supply of -5V to -10V and then reduce it with a linear regulator to -9V. The -5V itself comes from a positive supply, typically 5 or 12V. Independently creating each of the two negative voltages requires the use of two switching-regulator ICs....

Positive regulator makes negative DC/DC converter: 12/26/02 EDN Design Ideas / (added 1/05) Power-supply designers can choose from a plethora of available positive buck regulators that can also serve as negative boost dc/dc converters. Some buck regulators have a negative-feedback reference voltage expressly for this purpose, but ICs that have positive-reference feedback voltages far outnumber these negative-feedback regulators...

. Power Booster Applications - App Note 14: Apex Microtechnology Corp - App Note - (added 6/06)

Protection Feature Enhances Boost Converter: 10/27/94 EDN-Design Ideas / (added 2/06) A boost-topology switching regulator is the simplest solution for converting a two- to three-cell input to a 5V output. Unfortunately, boost regulators have several inherent disadvantages, including a lack of short-circuit protection and shutdown capability. In some battery-operated products, external chargers or adapters can raise the battery voltage to a potential higher than the 5V output. Because of this increase, a boost converter can't maintain regulation because the high input voltage feeds through the diode to the output...

Pushbuttons and Digital Potentiometer Control Boost Converter: 02/17/05 EDN Design Ideas / (added 11/05) Digitally controlled potentiometers are useful for generating analog control voltages under the control of a microcontroller. In some applications, manual pushbutton switches could replace a microcontroller and simplify product design. Mechanical switches exhibit contact bounce, and, when a user actuates them, they may open and close many times before reaching a stable state.

PWM Controller Drives LEDs from High Voltage Lines: 03/04/04 EDN Design Ideas / (added 6/06) Powering LEDs from a wide dc range—say, 30 to 380V—without wasting a lot of power in the regulating block, is a difficult task when the LED current needs to be constant. Dedicated LED drivers are available, but they usually implement boost structures and are thus inadequate for high-voltage inputs.

Regulated Step Up Converter Provides High Efficiency Without Inductors: Maxim Application Note #44 (app note added 7/03)

Relays: Transistor Boosted: (Circuit added 9/04)

Scheme Provides High Side Current Sensing for White LED Drivers: 02/19/04 EDN Design Ideas / (added 1/05) White LEDs find wide use in backlighting color-LCD screens in most portable devices, such as cellular phones, PDAs, and MP3 players. Multiple LEDs often connect in series to ensure that the same current flows through every LED. To forward-bias these LEDs, a voltage of 10 to 16V comes from an inductor-based boost regulator, such as an SP6690....

SEPIC generates 5V at 100 mA: 05/03/01 EDN-Design Ideas / (added 11/05) / PDF contains multiple circuits - scroll to find the one of interest / Some applications require an input voltage higher than the breakdown voltage of the IC supply pin. In boost converters and SEPICs (single-ended primary-inductance converters), you can separate the VIN pin of the IC from the input inductor and use a simple Zener regulator to generate the supply voltage for the IC. This design shows a SEPIC that takes a4 to28V input and generates5V at100 mA.

Short-Circuit Protection for Boost Regulators: DN154 - Design Notes (Linear Technology) (app note added 1/06)

Simple Boost Converter Generates 27 and 87V: 05/22/97 EDN-Design Ideas / (added 3/03)

Sine wave Step Up converter uses Class E concept: 02/17/05 EDN Design Ideas / (added 6/05) Many power applications ranging from luminescent and fluorescent lighting to telephone-ringing voltage generators require a more or less sinusoidal-drive voltage. These applications typically require a waveform of only moderate quality, and its frequency isn't especially critical. However, avoiding waveform discontinuities that cause unwanted current peaks, excessive device dissipation, and EMC...

Single Transistor provides short circuit protection: 10/16/03 EDN Design Ideas / (added 1/05) In certain dc/dc-converter applications, on-chip, cycle-by-cycle current limit may be insufficient protection to prevent a failure during a short circuit. A nonsynchronous boost converter provides a direct path from the input to the short circuit through the inductor and the catch diode. Regardless of current-limit protection in the IC, when a short circuit exists in the load, extremely high cu......

Step Up Converter for LED: Melexis Application Note (app note added 2/06)

Step Up supply charges battery while serving load : 06/08/95 EDN-Design Ideas / (added 11/05)

Step-Up/Step-Down Converter Takes 2 to 16V Inputs: 07/16/98 EDN Design Ideas / (added 11/05) The circuit in Figure 1 is a low-cost step-up/step-down dc/dc converter. By definition, its input can range above and below the regulated voltage. The circuit includes a simple switchmode boost converter (IC1) that contains a comparator normally used to detect low battery voltage. In this case, the comparator controls an external pnp transistor that operates as a linear regulator. IC1 steps up VIN (2V minimum) to the level of VX, as determined by the jumper block, J1.....

Supercapacitor Boosts Current from small Battery: 09/02/04 EDN Design Ideas / (added 1/05) Some battery-powered devices require large amounts of current in a short period of time but spend most of the time in sleep (power-down) mode. The momentary large-load current demands large batteries to meet the time requirement, even though the average current consumption is low. For instance, a system operates for 1....

Supply Derives 5 and 3.3V from USB Port: 12/20/01 EDN Design Ideas / (added 12/04) The circuit in Figure 1 derives its power from a USB port and produces 5 and 3.3V supply rails for portable devices, such as digital cameras, MP3 players, and PDAs. The circuit allows the port to maintain communications while, for example, charging a lithium-ion battery. IC2 boosts the battery voltage, VBATT, to 5V, and IC3 buck-regulates that 5V output down to 3. ...

The Use of Zetex E-Line Transistors in DC-DC Converters: An Introduction to the E-Line Package and Typical Applications: Zetec Semiconductors - Applications Notes - A basic guide to the DC-DC Converter requirement and concept, including an introduction to the Zetex enhanced TO92 - the E-Line package, and some suggested applications where these components offer advantages. (app note added 7/06)

Three input supply powers 3.3V portables: 04/13/95 EDN-Design Ideas / (added 6/06) The single-ended primary-inductance converter in Fig 1 accepts input voltages ranging from 3 to more than 6V and produces a regulated 3.3V, 200-mA output. The converter accepts an input voltage from three sources: a 5V dc wall cube, a three-cell AA battery, and a lithium backup battery. Unlike conventional boost regulators whose battery current continues to flow during shutdown (unless you add a cutoff switch), this circuit's output turns off fully in response to a shutdown command. And, unlike flyback-transformer regulators and combination step-up/linear regulators, Fig 1 requires no transformers. Coils L1 and L2 should be the same type and have the same value, but coupling between them isn't required. You can wind the inductors on the same core for convenience, but the circuit works equally well if they are completely separate....

Three parts provide tenfold increase in Switcher Current: 08/22/02 EDN Design Ideas / (added 1/05) Industrial-control circuits often derive their power from widely varying sources that can exceed the 40V maximum rating of popular switching ICs. This Design Idea presents a simple, flexible, and inexpensive buck switcher that converts an input voltage as high as 60V to 5V at several amps. The circuit is unique in that it boosts current with almost no compromise in performance, size, or cost....

Three-Band Equalizer: Using a single op-amp this easy to make equalizer offers three ranges, low frequency, mid frequency, and high. With component values shown there is approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz. Supply voltage may be anything from 6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage. (added 4/05)

Tiny and Efficient Boost Converter Generates 5V at 3A from 3.3V Bus: DN280 - Design Notes (Linear Technology) (app note added 1/06)

Tiny Highly Flexible Dual Boost/Inverter Tracks Supplies: DN357 - Design Notes (Linear Technology) (app note added 1/06)

TPS6102x Boost Converter Down Conversion Mode: TI Application Note (added 2/06)

TPS61042 White Light LED Driver Boost Converter (Rev. A): TI Application Note (added 6/06)

UCC3819 250-W Pfc Boost Follower Preregulator Design: This is an application note that describes a reference design.This paper reviews the benefits of a boost follower topology and the design of a 250-W PFC boost follower preregulator. (added 3/05)

Unique IC Buffer Enhances Op Amp Designs Tames Fast Amplifiers: AN16 - Linear Technology - This note describes some of the unique IC design techniques incorporated into a fast, monolithic power buffer, the LT1010. Also, some application ideas are described such as capacitive load driving, boosting fast op amp output current and power supply circuits.

Universal PSU: A Universal Power supply based on the L200 regulator, which includes an outboard pass transistor to boost output currents up to 4 amps. (added 7/06)

Use a Microcontroller to Design a Boost Converter: 03/04/04 EDN Design Ideas / (added 1/05) Boost converters, like other switchers, have traditionally received their control signals from a dedicated circuit. However, a recent trend is to integrate simple switching-power-supply building blocks into generic devices, such as microcontrollers. An excellent example of this concept is a microcontroller that combines digital and analog circuitry and makes it easier to build simple power supp......

Use of Zetex E-Line Transistors in DC-DC Converters: an Introduction to the E-Line Package and Typical Applications: Zetec Semiconductors - Applications Notes - A basic guide to the DC-DC Converter requirement and concept, including an introduction to the Zetex enhanced TO92 - the E-Line package, and some suggested applications where these components offer advantages. (app note added 7/06)

Buck regulator and two inductors make dual Polarity converter: 03/20/03 EDN Design Ideas / (added 1/05) A common problem for power-supply designers is to create a compact, dual-polarity step-down converter. If space and cost are not concerns, the obvious solution is a pair of dc/dc converters, one for each output. But space and cost are almost always issues for communications, data-acquisition, and disk-drive applications....

Buck regulator forms high Power inverting5V supply: 04/01/04 EDN Design Ideas / (added 1/05) Configuring a step-down switching-converter IC as an inverter yields an efficient, high-power, -5V supply that can of deliver currents as high as 4.5A at the 12V input or 3.2A at the 5V input (Figure 1). Conventional inverting power supplies do their switching using a p-channel MOSFET (Figure 2). That configuration works well at lower currents, but has limited use above approximately 2A, depend......

Buck Regulator Generates Flexible VTT for PECL: 08/15/97 EDN Design Ideas / (added 07/02) -- Circuit to generate Output which can both Source and Sink Current -- The positive emitter-coupled logic (PECL) in most high-speed clock-distribution and -recovery circuits requires a termination voltage, VTT, that imposes special requirements on the VTT supply. First, the typical switching thresholds for PECL must refer to VDD instead of ground (VOL=VDD1.32V+400 mV, and VOH=VDD1.32400 mV). The level of VTT, typically at VDD2V, is slightly below VOL to ensure that the open-emitter outputs always source current (Figure 1a). Unlike most power-supply voltages, therefore, the supply must regulate VTT with respect to VDD instead of ground....

Buck regulator operates Without a dedicated clock: 08/21/03 EDN Design Ideas / (added 1/05) Most switching regulators rely on a dedicated clock oscillator to determine the switching frequency of operation. A dedicated oscillator circuit within the power controller usually generates the clock signal. A class of hysteretic switching regulators can actually operate at a relatively fixed frequency without a clock, even with changing input-line and output-loading conditions....

Buck Regulator Terminates Fast Data Buses: 07/20/95 EDN-Design Ideas / (added 3/03)

Buck Regulator uses Step Up Controller: 11/09/95 EDN-Design Ideas / (added 3/03)

Buck/Boost Reference Design: This reference design presents an alternative to the typical boost power regulator. A buck converter IC is used to generate a higher voltage needed by the white light LED power from a Ni-Cd battery. This circuit operates by turning the high switch on, connecting the battery voltage across the inductor. Once sufficient energy is stored in the inductor, the high side switch is turned off. The inductor current drives the switching node negative and energy is delivered through the low side into the output capacitor. This is essentially a lossless switching event. Also, since the high side and low side switches are MOSFET's, voltage drop can be very low as compared to a diode implementation so efficiency can be high. Regulation is achieved by monitoring the current through the LED with a current sense resistor and comparing it to an internal 0.45 volt reference within the converter IC. Current and thereby, illumination is varied by modifying the current sense resistor voltage. (added 3/05)

Capacitor Improves Efficiency in CPU Supply: 04/04/02 EDN Design Ideas / (added 3/05) High efficiency is important for the dc/dc buck converters that supply high currents in notebook PCs. This efficiency extends battery life and minimizes temperature rise. A low-dissipation synchronous rectifier using an external MOSET provides this high efficiency. Synchronous rectifiers require special attention, however. ...

Cheap PWM IC Makes Synchronous Gate Driver: 02/04/99 EDN-Design Ideas / (added 6/06) A system with a µP, memory, and peripherals usually requires several power-supply voltages. Designers typically use local switching regulators to produce the desired voltage rails. One of the most common topologies, the synchronous buck regulator, converts a 5 or 12V bus to some other, lower voltage. This approach...

Constant on Time Buck Boost Regulator Converts a Positive Input to a Negative Output: 12/07/04 EDN Design Ideas / (added 11/05) Buck regulators find wide application as step-down regulators for converting large positive input voltages into a smaller positive output voltages. Figure 1 shows a simplified buck regulator that operates in continuous-conduction mode—that is, the inductor current always remains positive. The output voltage, VOUT, is equal to D×VIN, where D is the duty-cycle ratio of the buck switc...

Design Procedure for MicroProcessor Buck Regulators (AN-10): Application Note 10 from Microsem (app note added 6/06)

Designing a Multi Phase Asynchronous Buck Regulator using the LM2639: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

Simple Phone Tap: (electronic circuit added 7/03)

Surveillance Transmitter Detector: This circuit can be used to "sweep" an area or room and will indicate if a surveillance device is operative. The problem in making a suitable a detector is to get its sensitivity just right, Too much sensitivity and it will respond to radio broadcasts, too little, and nothing will be heard.

Three Transistor FM Radio Bug: (schematic / circuit (added 6/03)

10µA Quiescent Current Step-Down Regulators Extend Standby Time in Handheld Products: DN235 - Design Notes (Linear Technology) (app note added 1/06)

3A 2MHz Monolithic Synchronous Step-Down Regulator Provides a Compact Solution for DDR Memory Termination: DN309 - Design Notes (Linear Technology) (app note added 6/06)

Add an auxiliary Voltage to a Buck regulator: 10/31/02 EDN Design Ideas / (added 1/05) You often need more than one regulated output voltage in a system. A frequently used and reasonably simple way to create this auxiliary output voltage is to add a second winding to the output inductor, creating a coupled inductor or a transformer, followed by a diode to rectify (peak-detect) this output voltage....

AN-1144: Maximizing Start-Up Loads with the LM3352 Regulated Buck/Boost Switched Capacitor Converter: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

AN-1157: Positive to Negative Buck/Boost Converter using LM267X SIMPLE SWITCHER® Regulators: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

AN-1198: LM2622 Step-Up DC/DC Converter Evaluation Board: National Semiconductor - Application Note (app note added 2/06)

AN-667: Up/Down Sequence of Supplies Using the ADM1060: AN-667 - Analog Devices Application Note (app note added 6/06)

AN-H51: Buck/Boost-Based LED Drivers using the HV9910: Supertex Semiconductors (app note added 7/06)

Buck/Boost Charge Pump Regulator Powers White LEDs from a Wide 1.6 Volt to 5.5 Volt Input: Maxim Application Note #1021 (app note added 7/03)

Buck/Boost Regulator Suits Battery Operation: 09/04/03 EDN Design Ideas / (added 1/05) A buck/boost converter can step a voltage up or down. Such a converter is appropriate for battery-powered applications. One application derives a regulated 14.1V at 1A from 12V solar panels with 9 to 18V variation. In this type of battery application, efficiency is an important factor; hence, this design uses an inexpensive synchronous-rectifier-based MC33166/7 circuit....

Buck/Boost-Based LED Drivers using the HV9910: Supertex Semiconductors (app note added 7/06)

Constant on Time Buck/Boost Regulator Converts a Positive Input to a Negative Output: 12/07/04 EDN Design Ideas / (added 11/05) Buck regulators find wide application as step-down regulators for converting large positive input voltages into a smaller positive output voltages. Figure 1 shows a simplified buck regulator that operates in continuous-conduction mode—that is, the inductor current always remains positive. The output voltage, VOUT, is equal to D×VIN, where D is the duty-cycle ratio of the buck switc...

Get Buck/Boost Performance from a Boost regulator: 07/11/02 EDN Design Ideas / (added 1/05) The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output voltage that falls in the middle of the input-voltage range, such as a 5V output from a 2.7 to 6V input, The topology has some disadvantages, however. The efficiency of a SEPIC circuit fares worse than that of buck and boost regulators, and SEPIC desig......

Industry’s First 4-Switch Buck/Boost Controller Achieves Highest Efficiency using a Single Inductor: DN369 - Design Notes (Linear Technology) (app note added 1/06)

LDO Buck/Boost 2 Sync Buck Sync Boost Reference Design: LDO, Buck/Boost, 2 Sync. Buck, Sync. Boost with Vin 2.7-4.2 V LiION or 4.5-6.5 V adapter. Multiple output voltages of 1.5 V, 2.5 V, 3.3 V and 8 V. The total output power is 5.5 W. (added 3/05)

LTC1626: Step-Down Converter Operates from Single Li-ION Cell: DN196 - Design Notes (Linear Technology) (app note added 1/06)

Maximizing Start up Loads with the LM3352 Regulated Buck/Boost Switched Capacitor Converter: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

Micropower Buck/Boost Circuits Part 1: Converting Three Cells to 3.3V*: DN109 - Design Notes (Linear Technology) (app note added 1/06)

Micropower Buck/Boost Circuits Part 2: Converting Four Cells to 5V*: DN110 - Design Notes (Linear Technology) (app note added 2/06)

No Design Switiching Regulator 5V Buck/Boost (Positive to Negative) Regulator: DN49 - Design Notes (Linear Technology) (app note added 1/06)

Positive to Negative Buck/Boost Converter using LM267X SIMPLE SWITCHER® Regulators: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

Single Inductor Tiny Buck/Boost Converter Provides 95% Efficiency in Lithium-Ion to 3.3V Applications: DN275 - Design Notes (Linear Technology) (app note added 1/06)

Step Up/Step Down Current Source Charges Batteries: 06/06/96 EDN Design Ideas / (added 11/05) For battery charging, the highly efficient step-down (buck) configuration is usually the topology of choice. However, a different approach is necessary if the following conditions prevail: The supply voltage is less than the battery voltage, or, even worse, the supply voltage ranges above and below the battery voltage.

Step-Down Converter Operates from Single Li-ION Cell: DN196 - Design Notes (Linear Technology) (app note added 1/06)

Synchronous Buck Reference Design #2: This reference design is synchronous Buck/Boost converter that can deliver up to 3.8 A of continuous current at -5 V from a 5 V input. This topology uses a synchronous buck controller (TPS5103) referenced to the negative output rail. The synchronous MOSFETs allow this design to achieve a peak efficiency of 88%. In addition, the TPS5103 provides a soft-start function and over-current protection. (added 3/05)

Synchronous Buck/Boost High Power White LED Driver: Linear Technology LT3453 (app note added 2/05)

Up/Down Sequence of Supplies Using the ADM1060: AN-667 - Analog Devices Application Note (app note added 6/06)

4MHz Monolithic Synchronous Step-Down Regulators Bring High Efficiency to Space-Sensitive Applications: DN304 - Design Notes (Linear Technology) (app note added 6/06)

60V High Efficiency Buck Switching Regulators in SO-8: DN202 - Design Notes (Linear Technology) (app note added 1/06)

60V/3A Step-Down DC/DC Converter Maintains High Efficiency over a Wide Input Range: DN301 - Design Notes (Linear Technology) (app note added 1/06)

AN-1146: Designing a Multi-Phase Asynchronous Buck Regulator using the LM2639: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

AN-1197: Selecting Inductors for Buck Converters: National Semiconductor - Application Note (app note added 7/06)

AN-1253: Wide-Input, High Voltage Buck Converter: National Semiconductor - Application Note (app note added 2/06)

AN-1319: Analysis and Design of a Hysteretic Constant Frequency Buck Regulator using the LM5007: National Semiconductor - Application Note (app note added 7/06)

AN-6003 / 'Shoot-through' in Synchronous Buck Converters: Fairchild Application Notes / (app note added 6/06)

AN-6005 / Synchronous buck MOSFET loss calculations with Excel model: Fairchild Application Notes / (app note added 6/06)

AN793: Power Management in Portable Applications: Understanding the Buck Switchmode Power Converter: Microchip Application Note - Published 18-Jul-01 (app note added 2/06)

AN874: Buck Configuration High-Power LED Driver: Microchip Application Note - Published 4-Jan-06 (app note added 6/06)

AN968: Simple Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Analysis and Design of a Hysteretic Constant Frequency Buck Regulator using the LM5007: National Semiconductor - Application Note (app note added 7/06)

AN-H48: Buck-Based LED Drivers using the HV9910: Supertex Semiconductors (app note added 6/06)

Buck Boost Regulator Suits Battery Operation: 09/04/03 EDN Design Ideas / (added 1/05) A buck/boost converter can step a voltage up or down. Such a converter is appropriate for battery-powered applications. One application derives a regulated 14.1V at 1A from 12V solar panels with 9 to 18V variation. In this type of battery application, efficiency is an important factor; hence, this design uses an inexpensive synchronous-rectifier-based MC33166/7 circuit....

Buck Configuration High-Power LED Driver: Microchip Application Note - Published 4-Jan-06 (app note added 6/06)

Buck Converter Chargers also Provides System Power: 05/22/97 EDN Design Ideas / (added 4/02) -- Switching Regulator provides the charge voltage setpoint with Current regulation, and second Switching Regulator provides5V System Power -- Many systems require long-time operation during periods of power loss. Often, a gel or wet-cell lead-acid battery is the best choice because of high capacity and relatively low cost. The battery charges during normal operation and powers the system during power loss. These systems require a circuit to charge the battery as well as to regulate the system's VCC. The design must provide a current-limited voltage to the battery for charging and still develop system VCC in the charge or the discharge condition.....

Buck converter works efficiently from phone line: 02/15/00 EDN-Design Ideas / (added 2/06)

Buck or Boost: Rugged Fast 60V Synchronous Controller Does Both: DN370 - Design Notes (Linear Technology) (app note added 1/06)

Buck Reference Design: This reference design is a buck converter that can deliver up to 2A of continuous current at -24 V from an input range of -35 V to -75 V. By referencing the UCC3813 controller to the negative input rail, the N-channel MOSFET is easily driven. This design achieves a peak efficiency greater than 95%. The UCC3813 provides current mode control for excellent line and load transient response. (added 3/05)

Double Data Rate Power Supply using the Tl5002 Voltage Tracking Regulator: The TL5002EVM-180 synchronous buck converter provides a 12A reference design for evaluating the performance of the TL5002 PWM control IC and the TPS2837 MOSFET driver for Double Data Rate (DDR) memory applications. (added 3/05)

Dual High-Current Power Supply Kit: The National Semiconductor Power Supply Kit is designed around the National LM2636, a synchronous buck regulator. It provides over 28 amps of current with variable output voltages ranging from +1.3V to +3.3V. (added 3/05)

Dual Monolithic Buck Regulator Provides Two 1.4A Outputs with 2-Phase Switching to Reduce EMI: DN305 - Design Notes (Linear Technology) (app note added 1/06)

EP48 12 V 1.44 W Non-Isolated Buck Converter: This design kit is a non-isolated 12 V, 120 mA power supply utilizing a LNK304. This power supply is intended as a general purpose evaluation platform for LinkSwitch-TN in a buck converter configuration. (added 7/06)

Extend the input range of a Low dropout regulator: 10/17/02 EDN Design Ideas / (added 1/05) Because of process limitations, all ICs have an input-voltage limitation. This limitation can be cumbersome when you try to step down a high supply voltage to a lower, regulated voltage using a dc/dc converter, such as a linear regulator. Adding a FET to the input of a linear regulator creates a dc/dc converter with a wider input-voltage range than the range of the regulator alone....

Flyback LDO Buck Sync. Buck Reference Design: Flyback, LDO, Buck and Sync Buck with Vin 10 to 16 V. Multiple output voltages of -24 V, -5 V, 1.5 V, 3.3 V, 5 V, 12 V and 58 V. The total output power is 15 W. (added 3/05)

Get Buck boost Performance from a Boost regulator: 07/11/02 EDN Design Ideas / (added 1/05) The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output voltage that falls in the middle of the input-voltage range, such as a 5V output from a 2.7 to 6V input, The topology has some disadvantages, however. The efficiency of a SEPIC circuit fares worse than that of buck and boost regulators, and SEPIC desig......

High Current Step-Down Controller Regulates to 0.6V Output from 3V Input: DN322 - Design Notes (Linear Technology) (app note added 1/06)

High Efficiency Monolithic Buck Converter [LTC1265]: DN105 - Design Notes (Linear Technology) (app note added 6/06)

High Power Synchronous Buck Converter Delivers Up to 50A: DN156 - Design Notes (Linear Technology) (app note added 1/06)

High Voltage Buck Regualtors provide High Current Low Profile Power Solutions for FireWire Peripherals: DN287 - Design Notes (Linear Technology) (app note added 6/06)

High Voltage Current Mode Step-Down Converter with Low Power Standby Capability: DN383 - Design Notes (Linear Technology) (app note added 6/06)

High Voltage Low Noise Buck Switching Regulator [LT1777]: DN212 - Design Notes (Linear Technology) (app note added 1/06)

Hot Swap Push-Pull Sync. Buck Negative Flyback Dual Sync. Buck Reference Design: Hot Swap, Push Pull, Sync. Buck, Negative Flyback, Dual Sync. Buck with Vin of -36 V to -72V. Vout of 8 V, 5 V, 3.3 V, 2.5 V and -5 V. The output power is 79.5 W. (added 3/05)

IRDCiP1202-A 300kHz Dual 15A 5.5VIN to 13.2VIN Dual Output Synchronous Buck Converter using iP1202: This board allows engineers to easily evaluate the iP1202 in an independent and parallel configuration that is capable of providing up to 15A per phase with double-sided heat sinking. (added 6/06)

IRDCiP2001-A 500kHz 40A 2-phase Synchronous Buck Converter using iP2001: This board enables engineers to easily evaluate the iP2001 in a 2-phase configuration that is capable of providing up to 40A in a lab environment without airflow. (added 6/06)

Isolated Converters Have Buck Simplicity and Performance: DN377 - Design Notes (Linear Technology) (app note added 1/06)

LED Buck PFM: Powers LED with Constant Current Starting at 100MV over VF: This is a proof of concept circuit which needs improvement. The part values shown will run a high efficiency red LED with a Vf of 1.9V from only 2 nicads, right down to 2 volts. For a white LED you will need more batteries and you must increase the 1.0K resistor to a higher value. Current sensing at a mere 18mV over 1ohm makes this stepdown switcher efficient, but efficiency can be increased by using a larger inductor, improving transistor switching speed, or by increasing the value of the 1.0K resistor. ... (added 2/05)

LED Headlamps : This article includes circuits of DC-DC LED drivers step downs to run LEDs on less than Battery Volts, Boost for above. (added 4/02)

LM2675 5.0EVAL 1 Amp Step Down High Efficiency Simple Switcher Evaluation Board: National Semiconductor Application Note 10 Feb1999 (app note added 7/02)

Low EMI Synchronous DC/DC Step-Down Controllers Offer Programmable Output Tracking: DN382 - Design Notes (Linear Technology) (app note added 1/06)

Lower DC/DC Converter Ripple by using Optimum Capacitor Hookup: 10/31/02 EDN Design Ideas / (added 3/05) Low-ripple-voltage positive-to-negative dc/dc converters find use in many of today's high- frequency and noise-sensitive disk drives, battery-powered devices, portable computers, and automotive applications. Like a positive buck converter, a positive-to-negative converter can have low output-ripple voltage if you place the bulk input capacitor between VIN and VOUT rather than between VIN and gr......

LT1777 High Voltage Low Noise Buck Switching Regulator: DN212 - Design Notes (Linear Technology) (app note added 1/06)

Monolithic Step-Down Regulator Withstands the Rigors of Automotive Environments and Consumes Only 100µA of Quiescent Current: DN378 - Design Notes (Linear Technology) (app note added 6/06)

Monolithic Synchronous Step-Down Regulators Pack 600mA Current Rating in a ThinSOT Package: DN300 - Design Notes (Linear Technology) (app note added 6/06)

No Design Switching Regulator 5V 5A Buck (Step Down) Regulator: DN48 - Design Notes (Linear Technology) (app note added 1/06)

Obtain higher Voltage from a Buck regulator: 05/29/03 EDN Design Ideas / (added 1/05) Several semiconductor vendors'current-mode buck controllers have input-voltage ranges of 30 to 36V but have output-voltage ranges from the reference voltage to approximately 6V. This output-voltage constraint arises from the common-mode-voltage limitation of the current-sense amplifier. In real-world applications, the power-supply designer must be able to generate high output voltage for printe......

Off Line Buck Regulator Cuts Costs Leadtime: 10/26/95 EDN-Design Ideas / (added 3/03)

Power Management in Portable Applications: Understanding the Buck Switchmode Power Converter: Microchip Application Note - Published 18-Jul-01 (app note added 2/06)

Interface Cable for Casio Qv-200 Digital Camera: (electronic circuit added 4/05)

Kodak DC 20 Camera Interface (PIC12C509): (circuit / schematic design added 6/06)

Lightning Activated Camera Shutter Trigger: This circuit is used to trigger a camera's electronic shutter circuit when a flash of lightning is present. This circuit would also work for photographing fireworks displays or other events involving flashes of light. (added 10/05)

Adjustable Strobe Light: 120-Volt mains power source, up to20 Hz flash rate (added 4/02)

Flash Slave Trigger: Flash slaves are used when you need to supplement1-flash unit with1-or several more. This slave trigger simply triggers those other units. It does this by "seeing" the first flash (using a phototransistor) and triggering the other flashes a few microseconds later. The sensitivity of the circuit is adjustable to compensate for ambient light or dimmer than usual master flashes. (added 5/02)

LX1995 LED Driver: Camera Flash Application (AN-30): Application Note 30 from Microsem (app note added 6/06)

Miniature Strobe Light: (electronic Circuit / Schematic added 10/04)

Mini Pocket Strobe Circuit: works from two1.5-Volt AA batteries, based on modified camera flash unit (added 6/03)

Audio Acquires the Write touch: 02/20/03 EDN-Design Ideas / (added 11/05)

Capacitance Meter #1: (Circuit added 9/04)

Capacitance Meter #2: (added 8/03)

AN-829: Environmental Compensation on the AD7142: The Effects of Temperature and Humidity on Capacitance Sensors: AN-829 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Dual Comparators Stabilize Proximity Detector: 02/16/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Measure open circuited cables using a multimeter: 09/26/02 EDN Design Ideas / (added 1/05) You can use a multimeter with capacitance-measurement capability to measure the length of wire or cable to an open circuit. The capacitance of a pair of wires (or a wire to a shield) is directly proportional to the length of the wire. If you know the capacitance per foot of wire, then you can calculate how far it is to the open circuit....

Touch Activated Alarm: (added 10/02)

Using the AD7142 and a Capacitive Sensor to Develop a Single-Push Digital Shutter Button: AN-833 - Analog Devices Application Notes (added 2/06)

Fastest Finger First Indicator: (electronic Circuit / Schematic added 10/04)

Touch Activated Alarm (uoguelph_: (schematic / circuit added 10/02)

Touch Activated Lamp (ourworld): (circuit / schematic design added 6/06)

Touch Dimmer: (electronic Circuit / Schematic added 10/04)

Touch Switch Needs No DC Return Path: 02/03/05 EDN Design Ideas / (added 5/05) Common designs for touch switches detect a decrease in resistance when a user's fingertip either connects a contact to the circuit's common ground or supplies an injection of 60-Hz ac voltage, resulting from immersion in the electrostatic field that nearby power lines radiate. But what if no nearby power lines exist and the equipment operates from a battery source, such as in an automotive appl...

Ultracapacitor powers bicycle light: 09/28/00 EDN Design Ideas / (added 2/06)

Solar Cells implement Low Cost Illuminator: 09/12/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Memory termination IC balances charges on series capacitors: 08/18/05 EDN Design Ideas / (added 11/05) Get the best performance from high-value capacitors with simple IC circuit.

Mains Remote Alert: Remotely-operates a Beeper and/or a LED via mains supply line Simple Circuitry, easy to build unit (Circuit added 9/04)

Single NiCd Cell Drives OpAmp: 12/05/96 EDN-Design Ideas / (added 2/06)

Wireless Microphone #4: (Electronic circuit added 4/05)

Miniature MW Transmitter: circuit diagram of simple medium wave transmitter using BF494B. This simple transmitter have a range of 200 meters. . (Circuit added 9/04)

Miniature FM Transmitter #1: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #2: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #3: (Electronic Schematic / circuit added 4/02)

Selecting Inductors for Buck Converters: National Semiconductor - Application Note (app note added 7/06)

'Shoot-through' in Synchronous Buck Converters / AN-6003: Fairchild Application Notes / (app note added 6/06)

Simple Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Solar Step Down Regulator: (Circuit / schematic design added 6/06)

ST1S03 buck converters for hdd power supplies: AN2093 2. INTRODUCTION Purpose of This AppNote is to provide a brief summary of the specifications and the functionality of the application board.... (app note added 7/06)

Stepdown converter uses a ceramic output capacitor: 06/07/01EDN-Design Ideas / (added 7/03)

Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Sync. Buck with Integrated FET Forward Dual Sync. Buck Reference Design: Sync. Buck with Integrated FET, Forward, Dual Sync. Buck with Vin of 48. Vout of 15 V, 3.3 V, 1.8 V, 1.5 V. The output power is 47 W. (added 6/06)

Synchronous Buck circuit produces negative Voltage: 02/06/03 EDN Design Ideas / (added 1/05) Many electronic systems require both positive and negative voltages to operate properly. Generating an efficient, low-voltage positive output from a higher voltage input typically entails the use of a synchronous buck regulator. But when generating a negative output voltage from a positive input voltage, you'd typically use a flyback topology, especially at higher output currents....

Synchronous buck MOSFET loss calculations with Excel model / AN-6005: Fairchild Application Notes / (app note added 6/06)

Synchronous Buck Reference Design #2: This reference design is synchronous buck-boost converter that can deliver up to 3.8 A of continuous current at -5 V from a 5 V input. This topology uses a synchronous buck controller (TPS5103) referenced to the negative output rail. The synchronous MOSFETs allow this design to achieve a peak efficiency of 88%. In addition, the TPS5103 provides a soft-start function and over-current protection. (added 3/05)

Synchronous Buck Reference Design: This reference design is a 5Vdc input to 1.65V @ 1A output synchronous buck converter. The controller is the TPS40003 operating at 600KHz. The controller features Predictive Gate Drive, which minimizes the bottom FET body diode conduction time. This provides the benefit of increased efficiency when compared to a standard gate drive method. Very low output ripple voltage and excellent transient load performance are achieved with this design. (added 3/05)

Synchronous Flyback Circuit Provides High Efficiency Conversion: 07/22/04 EDN Design Ideas / (added 1/05) Buck regulators are usually the first choice when you design nonisolated step-down regulators unless the ratio of VIN to VOUT is greater than 10, the input voltage is high, or both. Low duty cycle can be problematic for FET drivers and cause current-mode control loops to lose control. Efficiency can fall dramatically to 60 to 70% at low VOUT and current of only a few amps.

ThinSOT Micropower Buck Regulator has Low Output Ripple: DN373 - Design Notes (Linear Technology) (app note added 6/06)

Tiny Buck Regulator Accepts Inputs from 3.6V to 25V and Eliminates Heat Sink: DN268 - Design Notes (Linear Technology) (app note added 6/06)

Tiny Step-Up/Step-Down Power Supply Delivers 3.3V at 1.3A in Battery-Powered Devices: DN271 - Design Notes (Linear Technology) (app note added 1/06)

Tiny Versatile Buck Regulators Operate from 3.6V to 36V Input: DN367 - Design Notes (Linear Technology) (app note added 6/06)

TSM108 Evaluatin Board 12V to 6V DC/DC Converter: The TSM108 is a step down controller that features constant voltage and constant current regulation.The Evaluation Board was designed to allow different converter configurations. Several options for power semiconductor footprints are available on the PCB in order to make it adaptable to a wide range of converter output power. In a first step, this application note will describe the typical application. Then the various options available on the Evaluation Board PCB will be explained. (app note added 6/06)

Two AA cells power step down regulator: 01/07/99 EDN-Design Ideas / (Schematic / circuit added 10/02) [Note: File contains multiple circuits - scroll to find this circuit] DC/DC conversion is particularly challenging when both the input and output voltages are low. Step-up ICs that operate with inputs lower than 1V are available, but step-down ICs that accept input voltages near 2V are not. Thus, providing efficient power for the low-voltage CPU in a handheld product can be a problem if the power source is a two-cell AA battery.....

Wide range regulator delivers 12V 3A output from 16 to 100V source: 06/23/05 EDN Design Ideas / (added 10/05) Buck regulator tackles high input voltages.

Wide-Input, High Voltage Buck Converter: National Semiconductor - Application Note (app note added 2/06)

Insect Repellant: (electronic design added 10/06)

Insect Repellant: (circuit / schematic added 2/03)

Mosquito Repellant: (added 9/02)

12C508 Smart Lock: base sends a data sequence ( password) which is recognized by key. key checks sequence and -if it recognizes it -sends to base anor data sequence, as an answer to password. At Time when base gets a correct answer (which means that key has been introduced), relay is put into action, and it can command a number of consumers. (added 4/02)

4 Digit Keypad: (circuit design added 8/03)

5 Zone Alarm Circuit: (design circuit added 8/02)

6A door lock motor driver for automotive: AN456AN456AN456AN456AN456 nal (OVV), put at low level enable of L9937, confirming hardware switch-off of motor ; in this condition an output of half bridge is in... (app note added 6/06)

Alarm Control keypad: (circuit design added 8/03)

Almost Ultrasonic Motion Sensor: (circuit design added 8/03)

Analog Video Router: Intersil Application Block Diagram (app note added 6/06)

Anti Theft Motorcycle Alarm: (electronic design added 9/02)

Anti-Bag-Snatching Alarm: (electronic Circuit / Schematic added 10/04)

Anti-Theft Alarm for Bikes: (electronic Circuit / Schematic added 10/04)

Anti-Theft Security for Car Audios: (electronic Circuit / Schematic added 10/04)

Automatic door opener with PIC12C508: This circuit can be used to operate an electric strike or an electromagnetic lock on a door. It is not door being opened/closed, but a small electromagnetic strike which unlocks door…. (added 4/05)

Basic RF Transmitter for PIR Sensors: (circuit design added 8/03)

Combination Lock: This circuit is very basic to build. To open a the lock which is connected to the K1 Load. you must press each momentary switch in the correct sequence. The sequence used in this circuit is S1,S2,S3,S4. If any of the other switches are pressed the circuit will reset and you will need to start over. Depending on how you wire the switches, you can use any4 switch combination (added 2/03)

Combination Lock (PIC16F84): (circuit design added 8/03)

Cut Phone Line Detector #1: Can be used to alarm security system (added 4/02)

Digital Combination Lock: (electronic design added 9/02)

Digital Electronic Lock: (electronic (schematic / circuit added 11/05)

Door/Window Sensor Resists Tampering: 01/21/99 EDN-Design Ideas / (added 11/05) The simple, inexpensive circuit in Figure 1 detects a failure (or deliberate tampering) on lines connected to normally closed switch sensors. For example, common door interlocks and door/window sensors consist of normally open or normally closed magnetic reed switches. Depending on the monitoring configuration, an open or short on a line may go undetected, thus preventing alarm activation. Embedding a resistor in a normally closed sensor and using bipolar dc power supplies produces the balanced configuration in Figure 1. A short or open on a line (or sensor activation) produces a net positive or negative voltage at the input of the Q1-Q2 pair....

AN34 ZXSC100 Power Supply for Digital Still Camera: Zetec Semiconductors Applications Notes Presented in this applications note is a typical sytem power supply design for a digital still camera. The solution is based on ZXSC100 DC-DC boost converter which provides an efficient and cost effective design. Conversion is from a two cell alkaline battery, 3V to 2V, to a regulated 3.3V output with a maximum load current of 100mA. All performance graphs associated with this design are provided in application note. (app note added 2/06)

Automatic -Exposure Scheme uses Ccd Shutter : 07/02/98 EDN-Design Ideas / (added 11/05) This application follows Design Idea, "Peak detector maximizes CCD-sensor range" (EDN, Aug 15, 1996). Its aim was to optimize performance of an A/D converter used to digitize a linear CCD sensor's analog output. The method involved stretching upper reference of flash ADC....

Camera Power and Video Use Same Coax Cable : 09/25/97 EDN-Design Ideas / (added 2/06)

Casio QV-200 Digital Camera Cable. : Lose your cable? Build it yourself and save $29. Fits many QV models. (added 6/06)

Debugging an MCU-based CCD camera controller: Agilent Application Note (app note added 6/06)

Miniature FM Transmitter #4: (add 9/04)

Cellular Phone Helper #2: (Circuit / schematic design added 6/06)

AN-42036 / PCB Grounding System and FAN2001/FAN2011 High Performance DC-DC Converters: Fairchild Application Notes / (app note added 6/06)

5V Power Supply Teams Low Dropout Regulator Charge Pump: 01/08/04 EDN Design Ideas / (added 1/05) Auxiliary power of 3.3V is replacing 5V auxiliary power that "silver boxes" supply in most computer systems, but some circuits still require a 5V supply. Such systems impose messy task of creating a central 5V auxiliary....

AN-348: Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Build a Charge Pump with UltraLow Quiescent Current: 09/05/04 EDN Design Ideas / (added 1/05) Portable battery-powered devices often spend most of ir life in standby mode, in which quiescent current of an internal boost converter continuously bleeds battery. The quiescent current during standby can be larger than actual load current......

Charge Pump Doubles Negative Voltage: Maxim App Note #782 (app note added 7/03)

Compact Inductorless Boost Circuit Regulates White LED Bias Current: Maxim Application Note #1116 (app note added 7/03)

Controlling a Variable Voltage Power Supply using the DS1809 (Pushbutton Control): Maxim Application Note #1035 (app note added 7/03)

AN-79: IC PreAmplifier Challenges Choppers on Drift: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Chopper Amplifiers Complement a DC Accurate Low-Pass Filter: DN9 - Design Notes (Linear Technology) (Circuit / schematic design added 6/06)

Chopping Reduces Reference’s Supply Current: 04/10/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Ultra Low Noise Op Amp Combines Chopper and Bipolar Op Amps: DN36 - Design Notes (Linear Technology) (added 2/06)

100 MHz Clock Solution for Desktop Computers: Pericom Semiconductor Application Brief # 021 (app note added 2/05)

68HC11 Stepper Motor Control: (circuit / schematic design added 6/06)

72 LED Clock: (electronic Circuit diagram added 03/03)

74ACT74 Makes Low-Skew Clock Divider: 12/17/98 EDN-Design Ideas / (added 11/05) Serial-data systems often generate an internal clock at twice data rate for mid-bit sampling or for generating bi-phase codes. External equipment and some internal processes require a clock that runs at data rate. Simply dividing twice-rate clock with a flip-flop generates a data-rate clock that is skewed by one logic delay with respect to input.....

AD9430 Evaluation Board Modifications for XTAL Oscillator Clocking: AN-616 Analog Devices Application Notes (app note added 6/06)

AN-291: Asynchronous Clock Interfacing with the AD7878: AN-291 Analog Devices Application Notes (app note added 6/06)

AN-616: AD9430 Evaluation Board Modifications for XTAL Oscillator Clocking: AN-616 Analog Devices Application Notes (app note added 6/06)

AN-657: ADN2812 Evaluation Board: AN-657 Analog Devices Application Notes (app note added 2/06)

AN-769: Generating Multiple Clock Outputs from the AD9540: AN-769 Analog Devices Application Notes (app note added 2/06)

Application of Zero-Delay Buffers in Switched Ethernet: Pericom Semiconductor Application Note # 015 (app note added 02/05)

Binary Coded Decimal (BCD) Clock (circuitdb): The clock circuit above uses seven ICs and 19 LEDs to indicate binary coded decimal time. The LEDs can be arranged (as shown in example above) so that each horizontal group of 3 or 4 LEDs represents.... (added 2/07)

Cheap 40kHz Clock: (electronic circuit added 7/03)

Chester's Propeller Clock: (design added 10/06)

Clock Recovery Scheme Suits Low Snr Systems: 06/05/00 EDN-Design Ideas / (added 6/06) A clock-recovery architecture can operate with NRZ digital signals, even at low SNRs. A clock-recovery subsystem is based on a PLL comprising a phase comparator, a loop filter, and a voltage-controlled oscillator (VCO)....

Clock Performance in Raid Storage Applications: PI6c2502: Pericom Semiconductor Application Note # 026 (app note added 02/05)

Clock Termination Techniques: Pericom Semiconductor Application Brief # 023 (app note added 02/05)

Crystal Considerations with Dallas Real-Time Clocks (RTCs): Maxim Application Note #58 (app note added 2/05)

Crosstalk on the Clock (Part 2): Maxim Application Notes / 1841 / Nov-04 (app note added 6/06)

ADN2819 Evaluation Board: AN-636 Analog Devices Application Notes (app note added 2/06) This application note describes use of ADN2819 evaluation board. The ADN2819 is a multirate clock recovery, data-retiming device based on a multiloop PLL architecture…..

Morse Code Practice Keyer #1: (added 10/02)

Morse Code Practice Keyer #2: (added 10/02)

30 Meter QRP Transmitter for Morse Code: (Circuit / schematic design added 6/06)

Morse Paddle Keyer: (Electronic circuit added 4/05)

Touch CPO: touch operated code practice oscillator using popular timer IC555. Practice Morse code in a different way. . (Circuit added 9/04)

Two Way Morse Practice Set: (added 2/05)

Color Organ #1: make different colored bulbs light at different frequencies of music, connects to speaker outputs (added 4/02)

Color Organ #2: one lamp color organ (added 4/02)

Color Organ #3: makes3 Light to blink and flash to music (added 7/03)

Colour (Sound) Organ: (electronic circuit added 4/05)

Simple Colour Organ: (electronic circuit added 4/05)

Wide Swing Variable Crystal Oscillator: (added 2/05)

4 Transistor Transmitter: (added 8/03)

Crystal Oscillators and Frequency Multipliers using the NE602 and NE5212: Philips Semiconductors Application Notes 1983, December 1991 (Electronic circuit design added 02/05)

LC (Colpitts) Oscillator operates on 0.5V to 5V Single Supply: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

NanoPower LC (Colpitts) Oscillator Circuits: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Positive Feedback: The use of positive feedback is useful for producing oscillators. The condition for positive feedback is that a portion of the output is combined in phase with the input. For an amplifer with positive feedback the gain is given by the expression below. (Electronic circuit design added 02/05)

Trimless IF VCO part 2: Maxim Application Note 688, February 5, 2001 (Electronic circuit design added 02/05)

Resonant Frequency of a Colpitts Oscillator: (Electronic circuit design added 02/05)

Use of the CMOS Unbuffered Inverter in Oscillator Circuit: Texas Instrument Application ReportSZZA043 January 2004 (Electronic circuit design added 02/05)

AN17 Emergency Lighting Systems and Battery Powered Fluorescent Lighting: High Current To92 Switching Transistors Provide 87% DC-AC Conversion Efficiency: Zetec Semiconductors Applications Notes An overview of principles behind typical emergency lighting systems, fluorescent tube behaviour, and requirements of transistors for efficient voltage inversion. The note also includes two "Royer" based designs for low voltage systems. (app note added 6/06)

Bidirectionall Power Inverter: (circuit added 1/07)

Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 6/06)

DAC ICs: How Many Bits Is Enough?: AN-327 Analog Devices Application Notes (app note added 6/06) Digital audio playback DACs are available in a variety of different architectures--each with it's own performance tradeoffs.

DC/AC Inverter (interq): (electronic circuit added 4/05)

Resistance, DC Current, AC Current, Frequency and Period Measurement Errors in DMMs (5988-5512EN): Aligent Application Note (added 4/08)

+5 to-15 Volts DC Converter: National Semiconductor - Application Note (app note added 2/06)

+30V Power Supply with +5V: I made the power supply which makes about +30V with +5V power supply.
The direct current is changed into the alternating current by the oscillator which used the schmitt trigger inverter which has the hysteresis characteristic and the resonance circuit. The high DC voltage (+50V) is made with the alternating voltage using the voltage amplification rectification circuit. (app note added 6/06)

1.3V Power Supply: This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer. (added 6/06)

3.3V lithium cell supply requires one inductor: 08/05/99 EDN - Design Ideas / (added 09/05) Because of the growing popularity of lithium-ion (Li-ion) batteries and 3.3V power supplies, portable-equipment designers must often create a 3.3V supply that a single Li-ion cell can power. The fact that the output of a Li-ion battery ranges above and below 3.3V during its discharge cycle complicates the design.

6 to 12 Volt Converter: This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful. (added 4/02)

9-V Stabilized Power Supply: (added 2/06)

60V Step-Down DC/DC Converter has Only 100µA Quiescent Current: DN1007 - Design Notes (Linear Technology) (app note added 1/06)

+/-5V Power Supply Operation with TC7106A/7107A (TC7106A/7107A): Microchip Application Note - Published 12-Nov-02 (app note added 6/06)

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Notes (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Analog Signal-Handling for High Speed and Accuracy.: AN-342 Analog Devices Application Notes (app note added 2/06)

Crystal Controlled Time Base Generator: (Electronic Circuit / Schematic added 10/04)

Crystal Oscillator overcomes typical Drawbacks: 08/17/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

JT-11ssp 6m as Input Transformer for Crystal Cs5367 A/D Converter: transformer balanced passive input circuit for CS5367 A/D converter, PDF file (Circuit / schematic design added 6/06)

Specifying Quartz Crystals: Maxim Application Notes / 726 / Dec-08 (Circuit / schematic design added 6/06)

Study of the Crystal Oscillator for CMOS CoPS: National Semiconductor Application Note 04 Nov1995 (circuit / schematic added 2/03)

Use of the CMOS Unbuffered Inverter in Oscillator Circuit: Texas Instrument Application ReportSZZA043 January 2004 (Electronic circuit design added 02/05)

Ultra Low Voltage Micropower Crystal Oscillator Circuit: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Analog multipliers take cube roots: 4/10/97 EDN-Design Ideas -- (electronic circuit added 5/'02)

13.8 Volt 20psu: This is a Regulated DC power supply with short circuit protection and with current limiter. (added 6/03)

Add-on Current Limiter: With buzzer (circuit added 11/06)

Circuit Provides Hiccup Current Limiting: 06/26/03 EDN Design Ideas / (added 1/05) Current-limit protection is an essential feature for power-supply systems. The three major types of current-limit-protection mechanisms are constant, foldback, and hiccup. Hiccup current limit performs the best of the three types; however, the implementation is rather complex. In this scheme, upon detection of an overcurrent event, the whole power supply shuts down for an interval before it tri......

Current-Limit Switch is Digitally Programmable: 08/17/00 EDN-Design Ideas / (added 2/06)

L200 Psu: easy to power supply with1-single L200 IC, offers a variable current limit of up to2 A, as well as voltage regulation (added 10/05)

Voltage Reference sets Current limit : 11/19/98 EDN-Design Ideas / (added 6/06)

4 to 20 Mloop Needs No External Power Source: 09/13/2001 EDN - Design Ideas / (Electronic circuit design added 02/05) The simple circuit in Figure 1 uses a low-current-drain MAX4073H amplifier to sense the current flowing through a 4- to 20-mA loop. The circuit senses the current through a 1Ω resistor with a fixed gain of 100 and uses no battery or dc power supply. The low current drain of the amplifier (0. .

Loop powers Current transmitter: 10/28/99 EDN-Design Ideas / (added 2/06)

Circuit forms novel floating current source: 05/01/03 EDN Design Ideas (added 1/05) Figure 1 shows a polarization circuit applicable to ISFET (ion-sensitive field-effect-transistor) sensors. ISFETs are solid-state chemical sensors that measure the pH value of a solution in biomedical and environmental applications, for example. The circuit in Figure 1 is extremely simple; it sets fixed-bias conditions for ISFET sensors (VDS=I0 RX; IDS=I0)....

A Simple Current-Sense Technique Eliminating a Sense Resistor (AN-7): Application Note 7 from Microsem (Circuit / schematic design added 6/06)

AN-D16: Lnd1 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

AN-D18: Dn25 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

Cascode Current Source : Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Constant Current Battery Charger: (circuit added 7/02)

Current Source and Sink Circuits Have Low Tc: 07/04/96 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Current Source Multiplication: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

A Closer Look at LVDS Technology: Pericom Semiconductor Application Note # 041 (Circuit / schematic design added 6/06)

An introduction to the CAN protocol that discusses the basics and key features.: Microchip Application Note - Published 16-Sep-05 (Electronic Circuit added 03/06)

AN-1074: CAN Products from National Semiconductor Users Guide and Application Note: National Semiconductor - Application Note (Electronic Circuit added 03/06)

AN515: Communicating with IIC Bus using PIC16c5x: Microchip Application Note - Published 26-Aug-97 (Electronic Circuit added 03/06)

AN971: USB Port-Powered Li-ION/Li-Polymer Battery Charging: Microchip Application Note - Published 31-Jan-05 (Circuit / schematic design added 6/06)

Design a Low Jitter Clock for High Speed Data Converters: Maxim Application Notes / 800 / Aug-05 (Circuit / schematic design added 6/06)

Design a Visible Optical Link for RS 232C Communications: 01/09/03 EDN Design Ideas / (Electronic Circuit added 03/06) The design in Figure 1 is a visible optical link for those who need to see the transmitted data. An isolation figure of more than 5000V is a bonus. Tests of the system used the COM input of a data-acquisition system, as well as a standard PC's COM port. The MC1489 converts the RS-232C data to TTL signals....

DS92LV010A Bus LVDS Transceiver Ushers in a New Era of High-Performance Backplane Design: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

CA3090 Stereo Decoder: Stereo Multiplex Decoder (circuit added 8/06)

LM1310 FM Stereo Decoder: Converts your mono FM Receiver to Stereo (circuit added 8/06)

LM1800 Stereo Demodulator: Phase-Locked Loop FM Stereo Demodulator (circuit added 8/06)

Remote Control Encoder/Decoder with PIC16c620 and PIC12c508: (circuit / schematic design added 6/06)

Use Your Printer Port as a High Current Ammeter: 07)/06/00 EDN-Design Ideas / (added 7/03) -With a few inexpensive components and INT1Ch, you can turn the printer port of your PC into a high-current ammeter....

High and Low Voltage Cutout with Delay and Music: Voltage variations and power cuts adversely affect various equipment such as TVs, VCRs, music systems and refrigerators. This simple circuit will protect the costly equipment from high as well as low voltages and the voltage surges (when power resumes). It also gives a melodious tune when mains power resumes. When mains voltage is normal,..... (added 10/05)

Feedback Circuit Eliminates CCD Driver Delay Mismatch: 09/18/03 EDN Design Ideas / (added 1/05) In a CCD (charge-coupled device), packets of charges shift across the array. The transistor array, also called a bucket-brigade shift register, receives drive from a dual-phase clock signal. Dual-phase clock signals comprise two synchronized clock signals that are 180° out of phase. High peak-output-current CCD drivers can buffer the logic-level clock signals and turn them into high-voltag......

Delay Line Implements Clock Doubler: 07)/18/96 EDN-Design Ideas / (added 3/03)

Butterworth Filter has Adjustable Group Delay: 08/08/02 EDN Design Ideas / (added 1/05) The Sallen-Key realization of a 5.25-MHz, three-pole Butterworth filter has a gain of 2V/V and can drive 75Ω back-terminated coax with an overall gain of 1 (Figure 1). Used to reconstruct component-video (Y, Pb, Pr) and RGB signals, this filter has an insertion loss greater than 20 db at 13.5 MHz and greater than 40 db at 27 MHz (Figure 2)....

Spread Spectrum Method Identifies Audio Path: 04/13/00 EDN-Design Ideas / (added 8/04) An unusual method of audio spread spectrum can identify the audio path that's currently in use through a consumer-electronic device. The design in Figure 1a uses an injected audio spread-spectrum tag signal because a listener does not notice the low...

Inverted Bipolar Transistor Doubles as a Signal Clamp: 11/09/00 EDN-Design Ideas / (Electronic circuit added 7/03) A number of circuits, such as level detectors and AM demodulators, benefit from a rectifier with a low offset voltage....

Demodulator Schematic/Design: The demodulator block diagram below has three major sections that were implemented in this iteration of the design, the mixer, the filter, and the phase shift network (Electronic circuit added 7/03)

Clock Recovery Scheme Suits Low Snr Systems: 06/05/00 EDN-Design Ideas / (Electronic circuit added 7/03) A clock-recovery architecture can operate with NRZ digital signals, even at low SNRs. A clock-recovery subsystem is based on a PLL comprising a phase comparator, a loop filter, and a voltage-controlled oscillator (VCO)....

Ber Meter is Easy to Build: 03/02/00 EDN-Design Ideas / (added 1/06) A bit-error-rate (BER) tester is a basictool for digital-communications measurements. Although many commercial BER testers are available, you can easily design and build an inexpensive version. The scheme in Figure 1 has performance similar to that of a commercial tester but requires you to perform a manual calculation based on displayed data. The tester displays received bits and received erroneous bits, and you must calculate the BER data using a handheld calculator, for example....

1-Wire Humidity Sensor: App Note 758: Maxim IC (application note added6/06)

741 Based Light Sensor: CdS photocell used for light/dark controlled relay (added 4/02)

Measure humidity and temperature on one TTL line: 08/30/01 EDN Design Ideas / (added 1/05) By combining the responses of an Analog Devices (www.analog.com) AD590 temperature sensor and a Humirel (www.humirel.com) HS1101 humidity sensor, you can generate a single TTL-level signal containing information from both sensors (Figure 1). This design uses a 74HC123 monostable multivibrator, IC1, to form a free-running oscillator. ...

Tiny Dew Sensor: (electronic Circuit / Schematic added 10/04)

Dew sensor: Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an inexpensive (resistor type) dew sensor element. Although dew sensor elements are widely used in video cassette players and recorders, these may not be easily available in local market. However, the same can be procured from....(added 11/06)

Synthesize Optimal Digital-Frequency Dividers: 05/13/99 EDN-Design Ideas / (added 11/05)

Clock Divider Circuit: (circuit / schematic design added 6/06)

Counter Provides Divide by 45 Function: 05/22/97 EDN-Design Ideas / (added 3/03)

Circuit divides frequency by N+1: 07/11/02 EDN Design Ideas / (added 1/05) Digital frequency dividers usually use flip-flop stages that connect the Q pin to the D data-input pin of the following stage. This configuration creates a binary waveform that you can feed back to the input. You can divide any integer lower than 2N with minimal stages, where N is the number of stages....

Birdie Doorbell Ringer: (schematic / circuit added 10/02)

Ding-Dong Bell: (electronic Circuit / Schematic added 10/04)

Doorbell with Counter: (circuit added 7/02)

Multi-Switch Doorbell with Indicators: (electronic Circuit / Schematic added 10/04)

Ask the Applications Engineer-2: AN-351 Analog Devices Application Notes (app note added 2/06) Trimming Offset and Gain in A/D's and D/A's

AN-711: AD5227 Evaluation Kit for the 64-Position, Up/Down Control Digital Potentiometer: AN-711 Analog Devices Application Notes (app note added 2/06)

AN-642: Coupling a Single-Ended Clock Source to the Differential Clock Input of Third-Generation TxDAC® and TxDAC+® Products: AN-642 Analog Devices Application Notes (app note added 2/06)

AN-420: Using the AD9708/AD9760/AD9701/AD9764-EB Evaluation Board: AN-420 Analog Devices Application Notes (app note added 2/06)

AN-336A: Image Compression-Spelling Out the Options: AN-336A Analog Devices Application Notes (app note added 2/06)

AN-318: AD7528 Dual 8-Bit CMOS Multiplying DAC: AN-318 Analog Devices Application Notes (app note added 2/06) This Application Note details a myriad of circuit applications made possible by multiplying characteristics and/or resistor ladder matching characteristics of AD7528.

AN-310: Single Supply 12-Bit DAC Circuits using the AD7568: AN-310 Analog Devices Application Notes (app note added 2/06)

AN-271: Applying the New CMOS Micro-Dacs: National Semiconductor Application Note (app note added 2/06)

AN-237: Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 2/06)

Square Wave to Sine Circuit: (Electronic circuit added 7/03)

+5V Switching regulator (1): (electronic circuit added 2/07)

12 Volt 30 Amp PSU: Using multiple power transistors to increase current of 7812 IC voltage regulator (circuit added 11/06)

2 Watt Switching Power Supply: from 6V to14V (added 4/02)

12 Volt DC to 120 Volt AC Inverter: this inverter should solve that problem. It takes12 VDC and steps it up to120 VAC. -Wattage depends on which transistors you use for Q1 and Q2, as well as how "big" a transformer you use for T1. inverter can be constructed to supply anywhere from1 to1000 (1 KW)-Watts. (added 4/02)

AB-11 / PC Board Layout Checklist: DC-DC Converters: Fairchild Application Notes / (app note added 6/06)

AN-4140 / Transformer Design Consideration for off-line Flyback Converters Using Fairchild Power Switch (FPStm): Fairchild Application Notes / (app note added 6/06)

Boost Controller Drives Buck Converter: 02/03/97 EDN Design Ideas / (added 3/05) -By adding an external Switching Transistor, you can use a step up dc/dc Converter to step down voltages to produce an efficient Battery Powered Power Supply, this example Circuit can step down inputs as Low as2V to Outputs as Low as1.25V, with efficiency as high as 80%

Buck/Boost Charge Pump Regulator Powers White LEDs from a Wide 1.6 Volt to 5.5 Volt Input: Maxim Application Note #1021 (app note added 7/03)

Build a Transformerless 12V to 180V DC/DC Converter: 07)/08/04 EDN Design Ideas / (added 1/05) Some transducers for portable or automotive applications need accurately regulated, high-voltage bias and draw little current. To produce such high voltages from a low battery voltage, designers typically use switch-mode dc/dc converters—generally, flyback converters. These converters exhibit high efficiency at medium or high output power.

1 Hz to 100 MHz VFC Features 160 Db Dynamic Range: 9/1/05 EDN Design Ideas / (added 10/06) Transform voltage to current over wide frequency, amplitude.

Photo-Diode Current-To-Voltage Converters: National Semiconductor Application Note (app note added 2/06)

Design Formulas Simplify Classic V/I Converter: 01/20/00 EDN-Design Ideas / (added 7/03)

Voltage-To-Current Conversion Amplifier: How to transform the passive voltage-to-current converter into an active one. (added 4/08)

Voltage to Current Converter Makes a Flexible Current Reference: 09/18/03 EDN Design Ideas / (added 1/05) The voltage-to-current converter in Figure 1 can both source and sink current. The circuit is more flexible than some traditional current references that require different topologies for current sourcing and sinking. Also, you can easily adjust the value of the current reference by simply adjusting the circuit's input voltage....

Ask the Applications Engineer (V/F Converters): AN-361 Analog Devices Application Notes (app note added 2/06)

AN-C: V/F Converter ICs Handle Frequency-To-Voltage Needs: National Semiconductor Application Note (app note added 2/06)

AN967: Bidirectional VF Control of Single and 3-Phase Induction Motors using the PIC16F72: Microchip Application Note Published 27-Jan-05 (app note added 6/06)

AN-361: Ask the Applications Engineer (V/F Converters): AN-361 Analog Devices Application Notes (app note added 2/06)

AN-277: Applications for the AD537 Voltage to Frequency Converter: AN-277 Analog Devices Application Notes (app note added 2/06)

Acceleration to Frequency Circuits: AN-411 Analog Devices Application Notes (app note added 2/06)

10 Khz VF0.02% V/F Converter Consumes Only 26 µA: 07/04/96 EDN-Design Ideas / (added 11/05)

C uses Charge Pump Variation: 04/09/98 EDN-Design Ideas / (added 3/03)

AN-C: V/F Converter ICs Handle Frequency-To-Voltage Needs: National Semiconductor Application Note (app note added 2/06)

Using the ADT7461 as a Multichannel Temperature Sensor: AN-702 Analog Devices Application Note (app note added 2/06)

Temperature-Based Fan Control using the MAXQ2000 Microcontroller: App Note 3620: Maxim IC (application note added6/06)

Thermofan to Keep Your Amp Cool: (circuit / schematic design added 6/06)

TC64X/TC64XB Demo Board for Fan Speed Controllers: Fan control module allows the user to quickly prototype fan control circuits based on the TC642 or TC646 PWM Fan Control IC's. Its uses though hole components for easy user assembly and evaluation. (app note added 6/06)

Suppressing Acoustic Noise in PWM Fan Speed Control Systems: Microchip Application Note Published 27-Jul-04 (app note added 2/06)

Speed Error in PWM Fan Control Systems (TC646, TC647, TC649): Microchip Application Note Published 27-Jul-04 (app note added 2/06)

MOSFET Switch Provides Efficient AC/DC Conversion: 02/17/00 EDN-Design Ideas / (schematic / circuit added 11/03)

Fan Speed Control is Cool!: App Note 1784: Maxim IC (application note added6/06)

Fan timer Based on Motorola 68HC908QT2: (circuit / schematic design added 6/06)

Computer Fan Speed Tacho Out Circuit: Add a Fan Speed Monitor Lead to Any 12V Two Wire Fan: You will find this identical circuit inside most 3 wire computer fans with speed monitoring output to the motherboard.
Peel off the sticker from the fan hub in order to access a motor winding pin for connecting up the tacho circuit. (added 2/05)

Circuit Generates Analog FAN-Speed Control: App Note 1125: Maxim IC (application note added6/06)

AN764: Implementing Temperature-Based Variable Fan Speed Control in Nlx Power Supplies: Microchip Application Note Published 4-Feb-03 (app note added 2/06)

AN-612: ADT7463 Configurations: AN-612 Analog Devices Application Note (app note added 2/06)

AN-699: Noise Filtering and the ADT7461: AN-699 Analog Devices Application Note (app note added 2/06)

AC line powers microcontroller-based fan-speed regulator: 11/9/2006 EDN Design Ideas / (added 02/07) Capacitor drops voltage, decreases waste heat in line-powered controllers.

AN-1262: Four-Speed Fan Control using Simple Remote Diode Temperature Sensor: National Semiconductor Application Note (app note added 2/06)

1 Second Time Base from Crystal Oscillator: (electronic circuit added 05/07)

2 Transistor Atomic Frequency Standard: (schematic added 8/03)

2.8 GHz prescaler keeps cost down: 07)/20/00 EDN-Design Ideas / (added11/05)

28 LED Clock Timer 72 LED Clock: programmable clock Timer circuit that uses individual LEDs to indicate hours and minutes (added 4/02)

40 LED Bicycle Light (555 Timer 6 Volt): (schematic added 8/03)

555 DC-AC Inverter: (circuit / schematic design added 6/06)

555 Go/No Go Tester: (schematic added 8/03)

555 Makes Handy Voltage to time Converter: 02/01/01 EDN-Design Ideas / (added 06/03) The circuit in Figure 1 is a simple, low-cost voltage-to-time converter using ubiquitous 555 timer chip. You can use IC's monostable multivibrator as a voltage-to-time converter by connecting analog-voltage input to charging resistor, R, instead of connecting R to VCC. With this modification,....

AN-1173: High Speed BUS LVDS Clock DistributionUsing the DS92CK16 Clock Distribution Device: National Semiconductor Application Note (app note added 2/06)

AN-349: Keys to Longer Life for CMOS: AN-349 Analog Devices Application Notes (app note added 2/06) Here's How CMOS Can be Protected Against Abuse

AN-214: Ground Rules for High Speed Circuits: AN-214 Analog Devices Application Notes (app note added 2/06) Layout and Wiring Are Critical in Video Converter Circuits.

Ad-03: Effects of Aperture Time and Jitter in a Sampled Data: National Semiconductor Application Note (app note added 6/06)

9 Second Digital Readout Timer: (circuit added 7/02)

9 Second LED Relay Timer: (circuit added 7/02)

Acquisition Times of the ADN2812: AN-757 Analog Devices Application Notes (app note added 6/06)

74ACT74 makes Low-skew clock divider: 12/17/98 EDN-Design Ideas / (added 11/05) Serial-data systems often generate an internal clock at twice data rate for mid-bit sampling or for generating bi-phase codes. External equipment and some internal processes require a clock that runs at data rate. Simply dividing twice-rate clock with a flip-flop generates a data-rate clock that is ....

Cheap Crystal filter: Ladder filter using six 4.43MHz Crystals. Building cheap side band filter for your bome brew SSB Rig. . (Circuit added 9/04)

1 Second Time Base from Crystal Oscillator: (Electronic circuit added 7/03)

AN-213: Low Cost, Two-Chip, Voltage-Controlled Amplifier and Video Switch: AN-213 Analog Devices Application Notes (app note added 2/06)

8 Hints for Making Better RF Counter Measurements: Agilent Application Note (Circuit / schematic design added 6/06)

Simplified Analysis of Phase-Locked Loop Capture and Tracking Range (AN 1200-7): Agilent Application Note (Circuit / schematic design added 6/06)

Microcontroller Makes Effective Frequency Counter: 11/23/00 EDN-Design Ideas / (Circuit / schematic design added 6/06)

Transition Counter Gauges Thermal Stability: 01/04/96 EDN-Design Ideas / (Schematic / circuit added 10/05)

Amplifiers Perform Precision Divide by 2 Circuit: 02/06/03 EDN Design Ideas / (added 1/05) The classic implementation of a voltage-halving circuit uses two equal-value resistors. Using 1% resistors provides a divider output with 2% accuracy. For most applications, this performance is cost-effective and more than adequate. However, when you need extreme precision, this approach requires correspondingly accurate resistors and can become expensive....

Cheap 40kHz Clock: (circuit / schematic design added 6/06)

Clock Divider Circuit: (circuit / schematic design added 6/06)

Counter Provides Divide by 45 Function: 05/22/97 EDN-Design Ideas / (added 3/03)

Applications of the LM392 Comparator Opamp Ic: National Semiconductor Application Note 04-Nov-1995 (app note added 4/02)

AN-87: Comparing the High Speed Comparators: National Semiconductor Application Note (app note added 2/06)

AN-41: Precision IC Comparator Runs from +5V Logic Supply: National Semiconductor Application Note (app note added 2/06)

An IC Voltage Comparator for High Impedance Circuitry: National Semiconductor Application Note (app note added 2/06)

Absolute Value Circuit Delivers High Bandwidth: 05/15/03 EDN Design Ideas / (added 1/05) Most absolute-value circuits have limited bandwidth and high component count, and y require several matched resistors. The circuit in Figure 1 uses three fewer components than most absolute-value circuits require, and only two of resistors must have 1% tolerance to obtain 1% accuracy. This circuit's output voltage is an accurate representation of absolute value of input signal,......

25-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

9 to 9 Pin (Female) Null Modem Cable: (circuit / schematic design added 6/06)

9-pin null modem cable: (circuit / schematic design added 6/06)

A Serial Infrared Remote Controller: (electronic circuit added 4/05)

AN-916: A Practical Guide to Cable Selection: National Semiconductor Application Note (app note added 2/06)

Apple Mac to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

Casio QV-200 Digital Camera Cable. : Lose your cable? Build it yourself and save $29. Fits many QV models. (added 7/03)

Commonly Used RS-232 Serial Port Cables: (design circuit added 8/02)

Interface Cable for Casio Qv-200 Digital Camera: (electronic circuit added 4/05)

Laptop Computer Serial Port Power Booster: (schematic / circuit design added 9/02)

8k and 16k Microwire EEPROM Enhancements: Microchip Application Note Published 11-Feb-04 (app note added 2/06)

7 Segment Rolling Display using PC: It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some ors as output lines. Some lines are open collector type which can be used as input lines. The circuit given here can be used for interfacing with any type of PC’s printer port. The 25-pin parallel port connector at back of a PC is a combination of three ports.. (added 10/05)

300 Baud Modem Circuit Schematic: Text is in French (added 4/05)

2m 20m Transverter: (circuit / schematic design added 6/06)

24 Line Parallel Interface for the PC : (electronic circuit added 7/03)

200 Watt Modified PC Power Supply 13.5 Volt 14 Amp: (electronic circuit added 4/05)

25 Watt MOSFET Amplifier: High Quality simple unit. No need for a Preamplifier (added 9/04)

25-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

2 Channel Port Powered RS-232 to RS422 Converter: information on commercial product, datasheet includes full circuit diagram (added 4/02)

2 Transistor Circuit Replaces IC #1: 02/07)/02 EDN-Design Ideas / (added 4/02) -Jim Hagerman's article Linear Technologies recently introduced LTC4300 chip buffers I2C clock and data lines to and from a hot-swappable card. This task is difficult because IC must work bidirectionally.

2 Transistor Circuit Replaces IC: Linear Technology's recently introduced LTC4300 chip buffers I2C clock and data lines to and from a hot-swappable card. This task is difficult because IC must work bidirectionally (added 08/05)

(AN-2) Ultra2 SCSI White Paper: Application Note Microsemi 1202 (added 2/07)

Salt Water Battery: (Circuit / schematic design added 6/06)

Variable Voltage Source: The high current regulator below uses an additional winding or a separate transformer to supply power for the LM317 regulator so that the pass transistors can operate closer to saturation and improve efficiency. For good efficiency the voltage at the collectors of the two parallel 2N3055 pass transistors should be close to the output voltage. The LM317 requires a couple extra volts on the input side, plus the emitter/base drop of the 3055s, plus whatever is lost across the (0.1 ohm) equalizing resistors (1volt at 10 amps), so a separate transformer and rectifier/filter circuit is used that is a few volts higher than the output voltage..... (added 4/05)

Signal Sources Conditioners and Power Circuitry: AN98 Linear Technology Eighteen circuits are presented in this compilation. Signal sources include a voltage controlled current source, an amplitude/frequency stabilized sine wave oscillator, a versatile, 0V to 50V wideband level shift and four sub-nanosecond pulse generators with risetimes as low as 20ps. Five signal conditioners appear; a unique, .... (added 9/06)

High Voltage Linear Regulator and Constant Current: Supertex Semiconductors (app note added 6/06)

Constant Current Battery Charger: (circuit added 7/02)

AN-D18: DN25 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

AN-D16: LND1 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

Build a Precise DC Floating Current Source: 08/18/05 EDN Design Ideas / (added 11/05) Use a general impedance converter and resistors to develop a specialized current source.

Circuit Simulates Contact Bounce : 05/08/97 EDN-Design Ideas / (added 2/06)

Switch Debouncer uses Only One Gate: 05/30/02 EDN Design Ideas / (schematic / circuit added 11/03) The circuit in Figure 1 produces a single debounced pulse each time you press S1. Moreover, the circuit uses only logic power from the remote pull-up resistor, R2. You can use the circuit to detect when a key is pressed in a nonenergized device, such as a device in a system that's just coming up from standby

Pushbutton Switch Debouncer: (electronic Circuit diagram added 03/03)

µC acts as dedicated motor control : 09/11/98 EDN-Design Ideas / (added 6/06)

µC Provides Wireless Keypad Control: 10/08/98 EDN-Design Ideas / (added 6/06) Portable systems, such as telephone handsets, make extensive use of low-dropout (LDO) regulators. se components provide noise-sensitive parts with a stable power-supply line. ....

12 Volt Strobe Circuit: this circuit uses12V DC instead od mains AC. This is very good idea if you don't want to mess with direct mains voltage connected circuit or you want to run stroboscope from batteries. (added 4/02)

2 Wire Remote Microphone Amplifier : (electronic circuit added 7/03)

230 Volt AC Motor Controller: controls speed of230-Volt AC universal motor, in PDF format, text in Finnish (added 6/06)

35kHz Magnetic-Radiation Remote-Control: (electronic circuit added 4/05)

80C31 Stepper Motor Controller: (electronic circuit added 4/05)

AN-327: DAC ICs: How Many Bits Is Enough?: AN-327 Analog Devices Application Notes (app note added 6/06) Digital audio playback DACs are available in a variety of different architectures--each with it's own performance tradeoffs.

Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 6/06)

DC/AC Inverter (interq): (electronic circuit added 4/05)

Emergency Lighting Systems and Battery Powered Fluorescent Lighting: High Current To92 Switching Transistors Provide 87% DC-AC Conversion Efficiency: Zetec Semiconductors Applications Notes An overview of the principles behind typical emergency lighting systems, fluorescent tube behaviour, and the requirements of the transistors for efficient voltage inversion. The note also includes two "Royer" based designs for low voltage systems. (app note added 6/06)

60V 3A Step-Down DC/DC Converter has Low Dropout and 100µA Quiescent Current: DN352 - Design Notes (Linear Technology) (app note added 6/06)

Passive Differentiator tops Active Designs: 04/28/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) The simple, passive differentiator in Fig 1 achieves accurate differentiation even at frequencies approaching the limit, fO=1/(2[pi]RC). The circuit surpasses the performance of an op-amp-based differentiator. The trick is to add a carefully selected inductor, [phi], to eliminate the first- and second-order terms in the equation for the phase angle, f, between the input and output signals. Ideally, of course, to achieve perfect differentiation, this phase angle should be equal....

µC controls digital potentiometer : 10/08/98 EDN-Design Ideas / (added 11/05)

10 Tricks for Interfacing to the PIC16c508: (electronic circuit added 7/03)

15-Step Digital Power Supply: (electronic Circuit / Schematic added 10/04)

32 Bit Serial Receiver (57.6 K Baud TTL and CMOS): (electronic schematic / circuit added 11/05)

51 MHz Frequency Counter Voltage Meter and SwR/PWR Indicator: (electronic Circuit diagram added 02/07)

68HC11 Instruction Halts External RC Clock: 04/27/95 EDN-Design Ideas / (added 3/03)

8 Hints for Debugging Microcontroller Based Design: Agilent Application Note (app note added 6/06)

8 Hints for Debugging Siemens MCU-based Designs: Agilent Application Note (added 6/06)

8051 Development System Circuit Board #2: (electronic circuit added 4/05)

9 Second Digital Readout Timer: (circuit / schematic design added 6/06)

µP Displays 10 Bit Data on Three LEDs: 11/07/96 EDN-Design Ideas / (added 08/05) circuit in Figure 1 uses a PIC16C55 µP to read 10-bit binary data and directly display data in decimal format on three common-cathode LED displays. If value of data exceeds 999, displays show three hyphens (---) to represent overflow. PIC16C55 has high drive capability. Each output pin can source 20 mA and sink 25 mA; outputs can thus directly drive LED display

9 Second Digital Readout Countdown Timer: This circuit provides a visual 9 second delay using a 7 segment digital readout LED. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output.... (added 3/07)

9 Second Digital Readout Timer: (circuit added 7/02)

Animated LED Signboard (PIC16C84): (electronic circuit added 4/05)

Connecting AT90S2313 with LCD Display 2x16 Char and 4x4 Keypad: (electronic circuit added 4/05)

Interfacing 16x2 Character LCD to Parallel Port: (circuit added 7/02)

µC implements Pushbutton Light Dimmers: 06/18/98 EDN-Design Ideas / (added 08/05) A project required building a synchronous-demodulator circuit to track a line drawn on paper. beauty of synchronous-modulator/demodulator approach is its inherent noise rejection. method rejects nearly all out-of-band noise, wher from internal drift or external illumination. This rejection is a boon in optical tracking, where return signal is inevitably buried in 120-Hz ambient light, amplifier offsets, and temperature drifts. circuit in Figure 1 is inexpensive, and it operates from 5V dc. circuit scans eight LED/sensor pairs every 22 msec and stores result in eight sample/hold (S/H) capacitors for interrogation by a µP-driven ADC. purpose of circuit is to determine which sensor is above line.

Circuit optimizes PhotoTransistor Bandwidth : 04/09/98 EDN-Design Ideas / (added 3/03)

Control Interface for Standard 0 - 10VDC Dimmers / ABR-42021: Fairchild Application Notes / (app note added 6/06)

A Ballast that can Be Dimmed from a Domestic (Phase Cut) Dimmer.: A system has now been developed, based around IR2156, where ballast is able to operate with minimal flicker over a considerable portion of adjustment range of a dimmer and light output may be controlled over this range from maximum output down to around 10%. (added 6/06)

4 Channel dimmer rack: (electronic circuit added 4/05)

8 Bit Digital Light Intensity Controller : (design circuit added 8/02)

A GPS Receiver Based Frequency Standard: (electronic circuit added 4/05)

Aisin-Seiki GPS-Receiver (Us$20 GPS): (electronic circuit added 4/05)

Alternative Power Source for Magellan GPS Receivers: (electronic circuit added 4/05)

Digital Compass Schematic: (electronic circuit added 7/03)

GPS Handheld: Intersil Application Block Diagram (app note added 6/06)

GPS Receiver Support Kit: (electronic circuit added 4/05)

Inertial Navigation System uses Silicon Sensors: 09/16/04 EDN Design Ideas / (added 1/05) A strap-down inertial-navigation system uses silicon sensors to measure displacement without entailing the bulk and expense of moving parts or GPS receivers. For example, a three-axis accelerometer and three angular-rate sensors can determine the position and velocity of a vehicle such as a robot or radio-controlled aircraft....

U-Blox GPS receiver Board: (electronic circuit added 4/05)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

16x16 LED Matrix and Driver: (circuit added 9/04)

2 Wire LCD Interface using PIC16cf84: (schematic / circuit design added 9/02)

20 Db Amplifier and High Current Balanced Line Driver: (circuit added 7/02)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 6/06)

72 LED Clock: (circuit added 7/02)

Digital Step Km Counter Max.: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)

Pedometer: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)

Unusual Frequency Dividers: (electronic circuit added 7/03)

66000 Modular Power System: Agilent Application Note (app note added 6/06)

9-V Stabilized Power Supply: (added 2/06)

6 to 12 Volt Converter: This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful. (added 4/02)

5 to 1.8V converter works without magnetics: 04/13/00 EDN-Design Ideas / (added 11/05)

3A Point-of-Load Power Supplies - MP1570 - DN0004: Monolithic Power Systems, Inc - Design Note - (added 6/06)

1119 Simple Regulator Provides ±12 Volt from 5 Volt Source: National Semiconductor Application Note 31 Aug2001 (app note added 7/02)

12 Volt 30 Amp Power Supply: uses a single 7812 IC voltage regulator and multiple outboard pass transistors, this power supply can deliver output load currents of up to30 amps (added 6/06)

0 to 300 Volt Adjustable Power Supply: This is a simple circuit that can provide an adjustable voltage source of0 to330 Volts. The supply is short-circuit proof: the current is limited to about100mA. (added 6/06)

+30V DC-DC converter: introduce the compact DC-DC converter in this page. I found this converter at the junk shop. I attempted to examine the characteristic of this converter. The input voltage is +5 V, the output voltage is +30 V and can get the about 20-mA output current. The IC(CD-1846P) to be using with this converter becomes the manufacturing stop already. However, TDK said that it was the discontinuation part and I could not acquire the data. Because it may become the reference when you use the similar circuit, I introduce in the contents of the converter. (app note added 4/05)

+5 to-15 Volts DC Converter: National Semiconductor - Application Note (app note added 2/06)

Ask the Applications Engineer 1-Multi Troubles: AN-354 Analog Devices Application Notes (app note added 2/06)

AN-759: Expanding the Number of DAC Outputs on the ADUC8xx and ADUC702x Families (uC012): AN-759 Analog Devices Application Notes (app note added 2/06)

12 V DC: 120 VAC Inverter Schematic: An Inverter is a device that converts 12 volts DC to 120 volts AC. , which is what we use in our homes. This project will handle about 300 watts, which is perfect for lights, small TV's and radio equipment. This Inverter takes 12 volt DC and steps it up to 120 volt AC. wattage depends on which transistors you use for Q1 and Q2, as well as "Amp Rating" of transformer you use for T1. This inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. If Q1, Q2 are 2N3055 NPN Transistors and T1 is a 15 A transformer, n inverter will supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power. Note: Don't try to run inductive loads (motors...) off this inverter. (added 4/05)

Two Tone Generator: This two-tone generator includes 3 ICs NE555 Astable Multivibrators. You can vary the duration of each tone by changing the 10k resistor or 100MF capacitor at IC1 or changing resistors and capacitors at IC1/2 for higher or lower tone. (added 6/03)

Simple Fix Adds Door-Chime Repeater: 05/13/99 EDN-Design Ideas / (added 11/05)

Automotive Relay Drivers using the Zvn4206av: Protection Free Interfacing with Avalanche Rated MOSFETs: Zetec Semiconductors Applications Notes An alternative solution is provided to usual large package Darlington effected relay driver. The ZVN4206AV has been designed, processed and rated to withstand significant energy within breakdown region. This allows part .... (app note added 2/06)

AT89C2051 Serial Coms to LED Driver: (circuit / schematic design added 6/06)

AT89C2051/4051 Driving Dot Led: (circuit / schematic design added 6/06)

AN-H20: HVCMOS Drivers for Non-Impact Printing: Supertex Semiconductors (app note added 6/06)

AN-H44: HV832 Dual EL Lamp Driver Circuits: Supertex Semiconductors (app note added 6/06)

(AN 30) LX1995 LED Driver: Camera Flash Application: Application Note Microsemi 1313 (added 2/07)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 2/07)

0 to 24 DB Gain Amplifier and Balanced Line Driver : (electronic schematic / circuit added 4/02)

12 Volt DC Fluorescent Lamp Driver: This fluorescent lamp driver uses a normal 120 to 6V step-down transformer in reverse to step12V to about350-Volt to drive a lamp without need to warm filaments. (added 6/06)

128x64 LCD Driver for AT90S2313 (Zip File) : (electronic circuit added 4/05)

16x16 LED Matrix and Driver: (circuit / schematic design added 6/06)

1a Flash LED Driver : Sipex Application Note (app note added 6/06)

20 DB Amplifier and High Current Balanced Line Driver : (circuit added 7/02)

Advanced IGBT Driver Application Manual: Application Note Microsemi 1903

AN-521: Dual Tone Multiple Frequency (DTMF): National Semiconductor Application Note (app note added 2/06)

AN-666: DTMF Generation with 3.58 MHz Crystal: National Semiconductor Application Note (app note added 2/06)

DTMF Decoder for PC: Displays DTMF digits on your computer screen in real-time. (circuit added 8/06)

Radio Remote Control using DTMF #2: Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals..... (added 09/05)

Simple 4-CH Remote Control: 4 channel remote control using MC145026, MC145027. (circuit added 8/06)

Radio Remote Control using DTMF: (electronic circuit added 10/05)

Synthesize Optimal Digital-Frequency Dividers: 05/13/99 EDN-Design Ideas / (added 11/05)

Clock Divider: (Circuit / schematic design added 6/06)

Charge Pump Doubles Negative Voltage: Maxim Application Note #782 (Circuit / schematic design added 6/06)

Frequency Divider Adapts to I / O Conditions: 09/29/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) CanadaThe circuit in Figure 1 accepts an input clock signal, such as from a crystal oscillator, and divides the frequency according to the input divisor word. You can easily modify the basicdesign of this versatile PLD-based ...

Make a simple PC based frequency meter: 04/29/99 EDN-Design Ideas / (added 11/05) A simple, low cost, and precision frequency meter uses only two pins of a pc parallel port (Figure 1). The TTL-level periodic input signal with frequency fIN connects to the ACK pin of LPT1. This input produces an IRQ7 hardware in- terrupt on every rising edge (Figure 2). The software counts the number of IRQ7 interrupts in the time unit of timebase T. If this timebase is 1 sec, the frequency of the input signal equals the number of IRQ7 interrupts in 1 sec....

Single Supply Operation of JFET Multiplexers: AN-32 - Analog Devices Application Notes (added 2/06)

Avoiding Passive-Component Pitfalls: AN-348 - Analog Devices Application Note (added 2/06) The Wrong Passive Component Can Derail Even the Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

AN-769: Generating Multiple Clock Outputs from the AD9540: AN-769 - Analog Devices Application Notes (added 2/06)

AN-35: Understanding Crosstalk in Analog Multiplexers: AN-35 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

AN-345: Grounding for Low-and-High-Frequency Circuits: AN-345 - Analog Devices Application Note (Circuit / schematic design added 6/06) Know Your Ground and Signal Paths for Effective Designs. Current Flow Seeks Path of Least Impedance-Not Just Resistance....

µC Based Circuit Performs Frequency Multiplication: 05/27/99 EDN-Design Ideas / (Circuit / schematic design added 6/06)

AN-249: over Voltage Protection for the ADG5XXA Multiplexer Series: AN-249 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit makes simple FSK modulator: 10/11/2001 EDN - Design Ideas / (added 11/03) The need for a compact telemetry system poses a challenge for designing a small, light, low-component-count system. Interfacing serial data from the microprocessor is also difficult because most low-cost RF transmitters do not accept dc levels at the input. Commercial FSK (frequency-shift-keying) modulators are bulky and need many passive components. .

Low Cost Programmable Oscillator Operates at 2 GHz: 05/11/00 EDN-Design Ideas / (added 7/03) All wireless communication systems need a local oscillator. Figure 1 shows a low-cost PLL circuit for the 2-GHz band for such applications as industrial, scientific, and medical (ISM) and satellite personal-communication systems (S-PCS). The central...

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Precision Voltage-To-Frequency Converter: AN-C: Application Note CV/F Converter ICs Handle Frequency-to-Voltage Needs, 3-Oct-02 (added 2/06)

New Phase Locked Loops: (Electronic Schematic / circuit added 4/02)

F/V Converter has High Accuracy: 05/12/94 EDN Design Ideas / (added 2/06)

Frequency-to-Voltage Converter uses Sample-and-Hold to Improve Response and Ripple: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02) -- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

Function Generator #2: (electronic (schematic / circuit added 11/05)

Function Generator #4: (schematic / circuit design added 9/02)

Function Generator #5: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Improve Function Generators with Matched D/A Converters: AN-322 Analog Devices Application Notes (app note added 6/06) AD7528 Dual 8-Bit CMOS Multiplying DAC Makes Function Generation Practical and Affordable

Using a Function/Arbitrary Waveform Generator to Generate Pulses: Agilent Application Note (added 6/06)

MAX038 Function Generator: This is a function generator that can generates 10Hz through 20MHz in six ranges. Analog output can select one of any wave forms, sine, triangle or square. TTL output can select 50% fixed duty or variable pulse width. (added 6/06)

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

AN-205: Video Formats and Required Load Terminations: AN-205 Analog Devices App Notes (app note added 2/06)

Adding HART® Capability to the AD421, Loop-Powered 4 mA–20 mA DAC using the 20C15 HART Modem: AN-534 Analog Devices Application Notes (app note added 2/06)

A Digitally Programmable Gain and Attenuation Amplifier Design: AN-137 Analog Devices Application Notes (app note added 2/06)

12-Bit Voltage-Output DACs for Single-Supply 5V and 12V Systems: AN-225 Analog Devices Application Notes (app note added 2/06)

µC RePrograms Audio DAC via Serial Interface: 01/07/99 EDN-Design Ideas / (added 08/05) [Note: File contains multiple circuits scroll to find this circuit] You can use a simple µC to continuously program an audio DAC so that it operates in a 20-bit resolution mode ( Figure 1 ). After power-on, PCM1710 delta-sigma DAC (Burr-Brown Corp, www.burr-brown.com) operates in its default 16-bit resolution....

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note Published 12-Nov-02 (app note added 2/06)

Two Diode Odd Order Multiplier: (electronic circuit added 7/03)

New Phase Locked Loops: (electronic (schematic / circuit added 4/02)

Hear Amateurs on Your FM Radio!: (electronic (schematic / circuit added 2/05)

Frequency Tripler using the Ca3028: (electronic circuit added 7/03)

Frequency Doubler Operates on Triangle Waves: 03/14/96 EDN-Design Ideas / (added 03/03)

Delay Line implements Clock Doubler: 07/18/96 EDN-Design Ideas / (added 3/03)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 4/02) -The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

900MHz Down Converter Consumes Little Power: 06/22/95 EDN-Design Ideas / (added 3/03)

555 Makes Handy Voltage to time Converter: 02/01/01 EDN-Design Ideas / (added 11/05) The circuit in Figure 1 is a simple, low-cost voltage-to-time converter using ubiquitous 555 timer chip. You can use IC's monostable multivibrator as a voltage-to-time converter by connecting analog-voltage input to charging resistor, R, instead of connecting R to VCC. With this modification,....

AN-279: Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage: 10/25/01 EDN Design Ideas / (added 1/05) The circuit in Figure 1 converts pulse information to a clean dc voltage by the end of a single incoming pulse. In another technique, an RC filter can convert a PWM signal to an averaged dc voltage, but this method is slow in responding. Converting low-duty-cycle pulse information is slower yet. ...

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Converter ignores Power Supply Variations: 01/05/95 EDN-Design Ideas / (Electronic circuit design added 02/05)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 1/04) -- PDF contains multiple circuits - scroll to find this circuit. --- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

42 Mc Band to 88 Mc Band (Retrofit Converters): (Electronic circuit added 7/03)

RF Frequency Linear Tuning Varactors: MicroNote 705 from Microsem (Circuit / schematic design added 6/06)

CMOS inverters convert RF to digital signal: 1/5/06 EDN Design Ideas / (added 10/06) Hex-inverter-based design suits frequencies up to180 MHz.

50 MHz to 146 MHz Converter: (added 2/05)

Zero Crossing Detector: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Time tag impulses with zero crossing circuit: 01/24/2002 EDN - Design Ideas / (added 11/03) A "constant-fraction discriminator" usually performs the time-tagging of impulsive events, which have a peaking time of the signal amplitude. The implementation of this technique requires a delay in the input signal of approximately the same amount as the signal's rise time. You can attain this delay by using a coaxial cable of an appropriate length.

Self Powered Sine to Square Wave Converter: Converts sine to square waves without a power-source Useful as a test instrument for audio purposes (Circuit added 9/04)

Voltage Controlled Oscillator ( VCO ): The oscillation frequency of the voltage controlled oscillator is controlled by the output of the PLL synthesizer and does the stable oscillation of 119.3 MHz. (Electronic circuit design added 02/05)

Pellistors: Pellistors employ catalytic combustion to measure combustible gases or vapors in air up to the Lower Explosive Limit (LEL)* of the gas. The standard sensor consists of a matched pair of elements, typically referred to as a detector and compensator (reference element). The detector comprises a platinum wire coil embedded within a bead of catalytic material. The compensator is similar except that the bead does not contain catalytic material and as a consequence is inert.(Electronic circuit design added 02/05)

MOSFET Current Mode Resonant Coil Driver: The schematic was made long after the circuit was built and perfected. Sorry. That means I cannot guarantee that it is free of errors. However, the schematic was compared to the original as best as I oould. ERRATTA: 1. The resistor network at pins 6 and 7 of the LM555 is incorrect. Instead of a fixed 200k and a 500k pot in parallel, it should be the 200k fixed in parallel with a 500k pot and the resulting two in series with a 1k fixed. Thus the 200k fixed established the maximum duty cycle, and the 1k pot establishes the minimum duty cycle. You could try eliminating the 1K, but you might damage the LM555. (Electronic circuit design added 02/05)

AN996: Designing a Digital Compass using the PIC18f2520: Microchip Application Note Published 8-Aug-05 (app note added 2/06)

Digital Compass Schematic: (circuit added 9/04)

Dinsmore 1490 Digital Compass: (electronic circuit added 4/05)

Electronic Compass Controller: Eventually we all want to know just where our robot is, so we can choose an absolute direction. Usually this type of device is quite expensive. However to our rescue comes.... (added 3/07)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

AN728: Remote Keyless Entry and Convenience Center Reference Design with LIN Bus Interface: Microchip Application Note Published 26-Sep-02 (app note added 2/06)

Combination Lock (PIC16F84): (electronic diagram added 6/03)

Combination Lock for Car Liftgate: (circuit / schematic design added 6/06)

Electronic Combination Lock with AVR: (electronic schematic / circuit added 2/05)

Electronic Card Lock System: (electronic Circuit / Schematic added 10/04)

Digital Electronic Lock: (electronic schematic / circuit added 11/05)

Single Button Lock Provides High Security: 03/04/99 EDN-Design Ideas / (added 5/03) Figure 1 is the block diagram of an easily programmed, single-button combination lock. You operate the lock by using a series of short and long pulses from a momentary switch that masquerades as a doorbell button. The circuit uses inexpensive CMOS logic. The retriggerable timer, T1, locks out entries made after the T1 code-entry window, thereby greatly enhancing security. The circuit in Figure 2 operates as follows: The Schmitt-trigger quad NAND gate, IC1, debounces the code-entry switch and, with the aid of simple analog circuitry, produces separate outputs for activation times of less than and more than 0.3 sec. These outputs connect to the select gate, IC5. The initial entry also sets timer T1 to enable the decoded decade counter, IC3. Each entry clocks IC3.

Simple Code Lock: (electronic Circuit / Schematic added 10/04)

Failed Power Light: turns on small low voltage lighting when mains power disappears (added 7/03)

Analog Encoding: Convert switches and sensors into DMX signals. Uses are found in Haunted houses, stage plays, med events, holiday light animations, anytime you want to control DMX compatible equipment. Fog machines and strobe lights can be independly controlled be remote switches or sensors. (added 02/05)

BA1404 Stereo Encoder: BA1404 used as only stereo encoder. (circuit added 8/06)

Digital Position Encoder Does Away withADC: 05/08/97 EDN-Design Ideas / (added 6/06)

KEELOQ® Manchester Encoding Receive Routines: Microchip Application Note Published 11-May-01 (app note added 2/06)

PIC Based Packet Radio Encoder: (circuit / schematic design added 6/06)

Remote Control Encoder/Decoder with PIC16c620 and PIC12c508: (circuit / schematic design added 6/06)

Rotary Encoder Mates with Digital Potentiometer: 02/06/03 EDN Design Ideas / (added 1/05) In developing electronic systems, designers look for products or ideas that may benefit from the better performance, smaller size, lower cost, and improved reliability that an IC can offer. Toward that end, the digital potentiometer emerged as an alternative to its mechanical counterpart, the mechanical potentiometer....

Veronica Stereo Encoder: Uses 76KHz crystal (circuit added 8/06)

SB-104: Fax Solution Card: National Semiconductor - Application Note (added 2/06)

Fax saver cuts wear, tear, and power: 1/8/98 EDN-Design Ideas / (added 4/'02)-- Less than $20 to cut wear and tear on your fax machine while saving power, circuit intercepts the incoming ring signal and powers up the fax machine in time to receive the fax and then turns off the fax machine after a predetermined time and awaits the next incoming fax

2 Watt Amplifier #1: (circuit / schematic design added 6/06)

2 Watt Amplifier #2: Low distortion Amplifier using discrete components (added 6/06)

2 Watt Amplifier #3: (schematic / circuit design added 9/02)

500W, Class E 27.12 MHz Amplifier Using A Single Plastic MOSFET: Application Note Microsemi-formerly Advanced Power Technology APT9903 ( app note added 2/07)

2N2222 40 Meter CW/DSB Tranceiver: (circuit / schematic design added 6/06)

AB-45 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-46 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-47 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-49 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

A Thermoelectric Cooler Temperature Controller for Fiber Optic Lasers: AN89 Linear Technology This application note presents circuitry for maintaining 0.01°C temperature control of fiber optic lasers over wide ambient range variations. The circuitry also features high efficiency power delivery, compact size and low noise. Detailed descriptions of circuitry and results are given with special emphasis on rmal loop optimization. An appended section covers practical considerations for rmoelectric cooler-based control loops.

DVD Applications / AB-46: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-47: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-49: Fairchild Application Notes / (app note added 6/06)

AN677: Designing a Base Station Coil for the HCS410: Microchip Application Note Published 7-Aug-98 (app note added 2/06)

Field Strength Meter (zen 22142): (electronic circuit added 7/03)

Field Strength Meter for the137 Khz Band: (electronic circuit added 4/05)

RF field strength meter Mk1: (schematic / circuit added e/07)

RF field strength meter: (electronic circuit added 3/07)

Fire Alarm: This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at the base of the transistor is pulled high due to which the supply to the COB (chip-on-board) is completed. Different COBs are available in the market to generate different sounds. The choice of the COB depends on the user. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity. An ON/OFF switch is suggested to turn the circuit on and off as desirable. (added 8/06)

60w Ac-DC Flyback Converter: Universal AC line input Fully assembled and tested power supply with DC containing all design documentation Features: 0-4A Iout @ 15V, 87% efficiency at high line, Short Circuit protection, Over Voltage protection (added 6/06)

Design Guidelines for RCD Snubber of Flyback / AN-4147: Fairchild Application Notes / (app note added 6/06)

Design Guidelines for Off-line Flyback Converters using FPS / AN-4137: Fairchild Application Notes / (app note added 6/06)

AN-H24: Expected Voltages and Waveforms HV9120-Controlled Flyback Converter: Supertex Semiconductors (app note added 6/06)

AN-777: LM2577 Three Output, Isolated Flyback Regulator: National Semiconductor Application Note (app note added 2/06)

AN-4137 / Design Guidelines for Off-line Flyback Converters using FPS: Fairchild Application Notes / (app note added 6/06)

Fluid Level Detector #1: (added 10/02)

Fluid Level Detector #2: (Electronic Circuit / Schematic added 10/04)

Fluid Level Control Systems Utilizing the LM1830: National Semiconductor - Application Note (added 2/06)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 3/07)

20ma LED Ballast: I use this circuit for general use to power white LEDs, like a headset light I use on my desk and a keyboard light for my computer. I built it into a tiny Radio Shack project box (270-288), which y no longer sell. I put heat-shrink tubing around female output connector (RS P/N 273-1743), so that contacts are not exposed, but you can still plug and unplug it. Designed by Andrew R. Morris (added 6/06)

A 3-Way Dimming Cfl Ballast: The 3 way dimming system widely adopted in US with conventional filament lamps consists of a light bulb that has a modified Edison screw type base which allows 3 connections to be made to a special lamp socket that also has 3 connections. (added 3/05)

40 Watt Fluorescent Lamp Inverter: This40W fluorescent lamp inverter allows you to run40W fluorescent tubes from any12V source capable of delivering3A. (added 4/02)

AN-378: A Novel Process for Vacuum Fluorescent (VF) Display Drivers: National Semiconductor Application Note (app note added 6/06)

AN-42001 / Low Cost Non-Dimming 220V Ballast Design: Fairchild Application Notes / (app note added 6/06)

Black Light: (circuit added 7/02)

2 Transistor FM Transmitters #2: (design added 8/03)

2 Transistor LED Flasher #1: (circuit / schematic design added 6/06)

10.7MHz FM Detector: (design added 8/03)

AN-146: FM Remote Speaker System: National Semiconductor Application Note (app note added 6/06)

AN-543 - Stereo FM Transmitter (DSP, 26,085 bytes): AN-543-StereoFMTransmitter-Analog Device Application Notes (app note added 6/06)

Crystal Controlled FM Transmitter: (circuit / schematic design added 6/06)

Add a signal strength display to an FM Receiver IC: 09/05/02 EDN Design Ideas / (Electronic Circuit added 03/06) The Philips (www.semiconductors.philips.com) TDA7000 integrates a monaural FM-radio receiver from the antenna connection to the audio output. External components include one tunable LC circuit for the local oscillator, a few capacitors, two resistors, and a potentiometer to control the variable-capacitance-diode tuning....

1W portable PLL transmitter: PLL oscillator with audio limiter. (circuit added 8/06)

2 Transistor FM Transmitters: (electronic Circuit added 03/06)

400mW VCO FM transmitter: BF199, BFR91, BFR96, varicap diode BB109. (circuit added 8/06)

Crystal Controlled FM Transmitter: (electronic Circuit added 03/06)

FM Radio Transmitter: (electronic Circuit added 03/06)

FM Transmitter (rf/2bjttx): (electronic Circuit added 03/06)

FM Transmitter with Opamp: L1 is 0.112uH (this tunes to the middle of the FM band, 98 MHz, with VC1 at its centre value of 33pF). L1 is 5 turns of 22 swg enameled copper wire close-wound on a 5mm (3/16") diameter former. Alternatively, you can have a fixed 33pF cap instead of VC1 and have L1 as an adjustable molded coil (eg UF64U from Maplin). VC1 will give you a tuning range of 85 125 MHz, and a possible choice is the Philips type polypropylene film trimmer (Maplin code WL72P). Two sets of oscillator bias resistors are given, the ones in the brackets give about 20% more RF power. Mike is our favorite Omni directional sub-mini electret (Maplin code FS43W). Ant is a (lambda / 4) whip monopole (eg 76 cms of 22 swg copper wire). Q1 is configured as a Clapp oscillator. Frequency modulation results from the audio voltage changing the transistor's base-emitter capacitance. (added 3/06)

LM110-An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Micropower Buffered Rail-to-Rail Adjustable Volatge Source: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Rail-to-Rail Voltage Follower/Buffer: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

High Input Impedance Source Follower: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

LB-11: The LM110: An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Base Current Compensated High Voltage Amplifier: Unpublished 1995 The base current of a single transistor high voltage amplifier varies from unit to unit and over temperature and current. To compensate, this opamp circuit measures base current and adds an equal but opposite current to input. (added 9/04)

A New Current-Differencing Quad of Plus or Minus Input Amplifiers: National Semiconductor - Application Note (added 2/06)

AN-1110:LVDS Quad Dynamic I Cc Vs Frequency: National Semiconductor - Application Note (added 2/06)

Get More Power Out of Dual or Quad Op-Amps: National Semiconductor - Application Note (added 2/06)

LM139/LM239/LM339 a Quad of Independently Functioning Comparators: National Semiconductor - Application Note (added 2/06)

Quad MOSFET Drivers for High: Supertex Semiconductors (app note added 2/06)

Quad Output Switching Converter Provides Power for Large TFT LCD Panels: DN349 - Design Notes (Linear Technology) (added 1/06)

CLC730145, CLC730132 (Soic and Tssop) Quad High-Speed Buffer Evaluation Boards: National Semiconductor - Application Note (added 2/06)

Laser Communication System: This is a simple Laser communication system. It can transmit and receive signal from any audio device.Communication distance is few meters. All components are not critical. Transistor 2N2222 may be on the coolrib. Laser diode is from laser pointer (Electronic circuit design added 02/05)

Cold Activated Switch: The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead type thermistor is found in the Maplin catalogue. The 100k pot allows this circuit to trigger over a wide range of temperatures. A slight amount of hysteresis is provided by inclusion of the 270k resistor. This prevents relay chatter when temperature is near the switching threshold of this circuit. (added 2/06)

Frost Alarm #3: (schematic / circuit design added 9/02)

Fridge Door Alarm: (circuit added 9/04)

Laser Link Communicator: audio transmission up to few hundred meters (Circuit / schematic design added 6/06)

4 Hints for Making Better Microwave Counter Measurements: Agilent Application Note (Circuit / schematic design added 6/06)

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Sunday, May 10, 2009

Electronics and Communication (ECE) Projects - Part 2

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