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Amplifier Circuits:  Operational
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Last Updated: November 30, 2017 07:38 AM

 
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One Op Amp achieves double-hysteresis-transfer characteristic -  09/27/07  EDN-Design Ideas An op amp combines with strategically placed zener diodes to yield a process-control circuit that has positive- and negative-going hysteresis bands __ Circuit Design by Herminio Martínez, Encarna García, and Juan Gámiz, Technical University of Catalonia, Barcelona, Spain

Op Amp as a Set/Reset Flip-Flop -  05/24/12  EDN-Design Ideas Eliminate a flip-flop package by using a spare op amp for an SR latch function.  You can make a set/reset flip-flop from two NAND or NOR gates or use readily available set/reset flip-flop ICs, such as the 74HC279 quad-set/reset latch.  The drawback of these methods is that they require a large amount of space to form the flip-flop.  Even if you need only one flip-flop, you must use a large IC package with this approach.  However, you can use a spare rail-to-rail op amp to perform the needed latch function (Figure 1). __ Circuit Design by Aruna Rubasinghe

Op Amp Bandwidth -  (spice design) __ Designed by Rick 

Op Amp Based FM Transmitter -  An low power FM Transmitter using an op-amp as the audio preamp and a single transistor as the RF amplifier. __ Designed by Kamran Ahmed

Op Amp can source or sink current -  03/02/06 EDN-Design Ideas   Bipolar current source beats familiar Howland-current pump __ Circuit Design by Alfredo H Saab and Steve Logan, Maxim Integrated Products Inc,  Sunnyvale, CA; Edited by Brad Thompson and Fran GranvilleMarch 2, 2006

Op Amp Comparator & Reference IC Provides Micropower Monitoring Capability Design Note 190 -  DN190 Design Notes__ Linear Technology/Analog Devices

Op Amp Comparator & Reference IC Provides Miscropower Monitoring Capability -  Design Notes 190__ Linear Technology/Analog Devices

Op Amp Comparator with Hysteresis with SPICE simulation -  The challenge sounds simple enough, take a 60 Hz (or 50 Hz) sinewave from the AC power line and convert it to a square wave.  This signal will serve as a clock to drive counters for a 24 hour time clock.  So you hook up an op amp as a comparator to do the job.  But your surprised to see the clock running too fast! With oscilloscope in hand you discover the AC line is noisy! And to your horror, you see glitches (spice design)



Op Amp Differentiator-Open Loop Analysis -  (spice design) __ Designed by Rick 

Op Amp Feedback Analysis -  (spice design) __ Designed by Rick 

Op Amp Improves Power Supply's Regulation -  6-Jun-96 EDN-Design Ideas A typical power supply has a voltage-regulation specification of 2 to 3% for all conditions, including initial setting, line, load, and temperature.  You can improve regulation if the power-supply has remote-sensing capability, however __ Circuit Design by Jimmie D Felps, Hewlett-Packard, Colorado Springs, CO

Op Amp increases potentiometer's resolution -  06/05/00 EDN-Design Ideas A key parameter of digitally controlled potentiometers(DCPs] is the number of taps(n] programmable positions of the wiper.  This parameter establishes the resolution in  programmable-voltage and -current applications.  A number of circuitPDF has many circuits, please scroll to find this one __ Circuit Design by Chuck Wojslaw, Xicor Inc, Milpitas, CA, and P Gareth Lloyd, Elab Ltd, Stoke-on-Trent, UK

Op Amp Input Voff & Ibias -  (spice design) __ Designed by Rick 

Op Amp Limiter -  (spice design) __ Designed by Rick 

Op Amp linearizes attenuator control response -  07/25/02 EDN-Design Ideas Professional-audio equipment commonly uses Analog Devices'(www.analog.com] high-performance, quad-voltage-controlled SSM2164 attenuator.  The control response is -30 dB/V, with 0V producing unity gain.  Attenuation increases as the applied control voltage increases in the positive direction.  The circuit in Figure 1 extends the range of applications for this versatile chip by providing a simple __ Circuit Design by Mike Irwin, Shawville, PQ, Canada

Op Amp linearizes response of FET VCA -  09/05/02 EDN-Design Ideas   FETs find common use in VCAs(voltage-controlled amplifiers]and attenuators, in which the FET serves as a variable resistance.  A control voltage applied to the gate sets the channel resistance and overall circuit gain __ Circuit Design by Mike Irwin, Shawville, PQ, Canada

Op Amp Macro-Models -  (spice design) __ Designed by Rick 

Op Amp makes precise 9V-battery splitter -  07/17/97 EDN-Design Ideas Alkaline 9V batteries are ideal for many portable, handheld applications, this circuit generates a bipolar supply of5V and ­2.3 to ­4V using a precision5V reference and one op amp as a supply splitter __ Circuit Design by Steve Hageman, Hewlett-Packard, Santa Rosa, CA

Op Amp PID Controller -  We've all heard about the wonders of the PID controller, bringing a system's output, temperature, velocity, light, to its desired set point quickly and accurately.  But now, your boss says okay, design one for us.  Although there's a number of ways to do it, the circuit above nicely separates the three terms (spice design)

Op Amp Provides On-The-Fly Adjustable Current Limit -  DN298 Design Notes__ Linear Technology/Analog Devices

Op Amp Radio -  Here is a simple radio that is easy to build and inexpensive.  In fact, you probobly have all the parts you need in your junk box.  You'll be suprised at the great reception with this little set. __ Designed by Aaron Cake

Op Amp Triangle-Wave Generator & SPICE simulation files -  This signal generator gives you two waveforms for the price of one: a triangle-wave and a square-wave. What is the central component of this circuit? The integrator capacitor CI|

Op Amps Make Automatic-Oring Power Selector -  08/11/11  EDN-Design Ideas Replace diodes with FETs to reduce power loss.  Many systems must select among two or more low-voltage dc-input sources, such as an ac adapter, a USB (Universal Serial Bus) port, or an onboard battery, for example.  You can implement this selection using manual switches, but automatic switching is preferable.  You usually want to use the highest-available input voltage to power your system.  You can accomplish this task using a Schottky-diode ORing scheme (Figure 1).  Unfortunately, the forward-voltage drop of a Schottky diode ranges from 300 to 600 mV.  This voltage wastes power, creates heat, and decreases the voltage available to your system. __ Circuit Design by Bob Zwicker, Analog Devices, Fort Collins, CO

Op Amps make JFETs repeatable -  05/24/01 EDN-Design Ideas Because they use practically no bias current(a useful feature in itself), JFETs also have practically no current noise.  This feature means that you can use JFETs in very-high-resistance circuits and obtain good noisePDF has many circuits, scroll for this one __ Circuit Design by Glen Brisebois, Linear Technology Corp, Milpitas, CA

Op-amp Astable Timer -  An astable timing circuit made from the ubiquitous 741 op-amp. __ Designed by Andy Collison

Op-Amp based battery voltage Monitor -  An ECU must have a way to monitor battery voltage.  Here is a simple op-amp based circuit which will illuminate the LED when the battery voltage drops to a certain level.  The turn-on point is set with R2.  You must be able to vary Vcc   (usually with a good power supply) to set the circuit.  Decide at what voltage you'd like the LED to illuminate, and apply this at Vcc.  Adjust R2 until the light just illuminates.  Use an LED which will light at the desired voltage level, and determine R3, using ohm's law   (E=IR), to keep the current flowing through the LED and op-amp to around 10mA.

Op-amp based Nv nets -  A more complex, but more flexible way of implementing bicores and quadcores and such.  At first glance, just another bicore variation, but with a higher component count.  It seems to reverse the BEAM drive toward simplicity (i.  e.  , more parts, no apparent increase in functionality).  But wait __ Contact: Eric Seale

Opamp Based Power Amplifier -  This is a contributed project, and has some interest as a learning exercise __ Designed by Rohit Balkishan

Opamp Basics -  The op-amp is basically a differential amplifier having a large voltage gain, very high input impedance and low output impedance.  The op-amp has a "inverting" or (-) input and "noninverting" or (+) input and a single output.  The op-amp is usually powered by a dual polarity power supply in the range of +/- 5 volts to +/- 15 volts.  A simple dual polarity power __ Designed by Bill Bowden

OpAmp Doubles as Instrumentation Amp -  09/15/94 EDN-Design Ideas The circuit in Fig 1 shows an ordinary, off-the-shelf, general-purpose op amp configured as an instrumentation amplifier.  Such a configuration yields an instrumentation amplifier having higher bandwidth than currently available dedicated instrumentation/ __ Circuit Design by Moshe Gerstenhaber and Mike Gianino, Analog Devices, Wilmington, MA

Opamp Integrator -  The integrator basically works like this: whatever current I you get flowing in R1, gets integrated across capacitor C1.  The output voltage Vo is simply the voltage across C1.  One great application of the integrator is generating a ramp voltage.  You can do this by placing a fixed voltage|

OpAmp Linearizes Response of FET VCA -  09/05/02 EDN-Design Ideas   FETs find common use in VCAs(voltage-controlled amplifiers]and attenuators, in which the FET serves as a variable resistance.  A control voltage applied to the gate sets the channel resistance and overall circuit gain __ Circuit Design by Mike Irwin, Shawville, PQ, CanadaSeptember 5, 2002

Op-Amp Microphone Preamplifier -  A high quality microphone preamplifier using a single power supply, suitable for dynamic or electret microphones.  The op-amp used can be any low noise, high performance type, e.  g.  NE5534, TL071, OPA 371 etc __ Designed by Andy Collison

Op-Amp Oscillators Simplify RF Design -  10/10/96 EDN-Design Ideas Figure 1 shows a novel circuit that uses a low-cost, high-speed op amp as a crystal-controlled RF sine-wave oscillator.  An op-amp oscillator offers several advantages.  Because an op amp is a complete amplifier with a high-impedance input __ Circuit Design by Charles Kitchin, Analog Devices, Wilmington, MA

Opamp Radio -  Here is a simple radio that is easy to build and inexpensive.  In fact, you probobly have all the parts you need in your junk box.  You'll be suprised at the great reception with this little set. __ Designed by Aaron Cake

Op-Amp Rectifier Signals Input State -  07/21/94 EDN-Design Ideas The op-amp rectifier in Fig 1 operates from a single supply and provIdeas a logic output and an LED that indicate the state of the input voltage.  The input-state indications are handy for calibration.  Because the circuit operates from a single supply, the 2.5V reference determines the level around which the circuit rectifies input waveforms __ Circuit Design by Lee E Scaggs, High Country TEK, Nevada City, CA

Op-Amps Basics for the beginner -  The 7 Basic Circuit Configurations for op-amps __ Designed by G.L. Chemelec

Op-Amps Basics for the beginner. -  The 7 Basic Circuit Configurations for op-amps __ Designed by G.L. Chemelec

Operational Amplifier gain & DC offset program -  Presented here is a program to find the gain and DC offset values of an operational amplifier (or op-amp).  While doing practical electronics experiments,|

Operational Amplifier Selection Guide for Optimum Noise Performance #2 -  DN3 Design Notes__ Linear Technology/Analog Devices

Optical Smoke Detector -  This optical smoke detector uses a low-cost, readily-available, slotted, through-scan, infrared photo-switch.  When smoke is detected, the relay energises to activate the audio/visual warning alarm.  Fig.1 shows the circuit of the __ Electronics Projects for You

Overcurrent & Undervoltage Battery Fault Protection -  The LT6109 is a complete high side current sense device that incorporates a precision current sense amplifier, an integrated voltage reference and two comparators.  Two versions of the LT6109 are available.  The LT6109-1 has the comparators connected in opposing polarity and the LT6109-2 has the comparators connected in the same __ Linear Technology/Analog Devices App Note, Sep 7th 2011

Overcurrent Battery Fault Protection -  The LT6108 is a complete high side current sense device that incorporates a precision current sense amplifier, an integrated voltage reference and a comparator.  Two versions of the LT6108 are available.  The LT6108-1 has a latching comparator and the LT6108-2 has a non-latching comparator.  In addition, the current sense amplifier __ Linear Technology/Analog Devices App Note, Sep 7th 2011

Over-Heat Detector -  NTC thermistors are often the preferred choice for temperature sensing and control in many applications, primarily because of their small package sizes and attractive price-performance ratios.  An NTC thermistor’s sensitivity to __ Electronics Projects for You


Operational Amplifiers:  #'s - A        B - C      D - K       L - N       O       P - S        T - Z 


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