An op-amp (operational amplifier) is a high gain analog voltage amplifier with differential high impedance inputs, and a low impedance output. A basic building block in signal processing, like as amplifier or active filter.

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Differential Input to Single Ended Output with Fully Differential Amplifier?

I am using LT1994 Fully Differential Input/Output Amplifier for a single-input to differential output configuration with no problem. I need to use same amplifier for differential input to single-...
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51 views

What can I do for this glucose meter circuit?

simulate this circuit – Schematic created using CircuitLab Hi guys! I am making a two-cell glucose meter. Here is may design. Of course, as you see, there are many problems that I cannot figure ...
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73 views

Analog computer using op-amp [on hold]

I have to design a analog computer using minimum number of op-amps to solve 4A+2B-3(A-C+D)=V equation(here A,B,C,D are inputs and V is the output) I know how to do simple adders but this one ...
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35 views

low pass filter and gain calculation

I am working on a data acquisition system project . I have used SMPS power supply and two pressure sensors(-5V to +5V input) and (0-20mV o/p) my analog circuit consists of one op-amp(OP07) and one ...
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2answers
55 views

Type J Thermocouple Signal Conditioning to 0-5V

I've been working with signal conditioning, thermocouple out specifically. I'm working with a span of 450 °C, that is, from -50 °C to 400 °C. For those values of temperatures I get, according to the ...
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69 views

LM358 Operational amplifier Ouput voltage rising with stable inputs

I'm modifying a step-up circuit based on UC3843 SMPS Controller to add a current limiting feedback to it. I'm using a low-side sense resistor (Rsense) amplified by an LM358: simulate this ...
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2answers
66 views

Choosing a suitable Opamp to output a voltage reference

Part 1: the circuit and how it's connected I'm trying to take from the 2.5V coming from a voltage reference IC AD780 to go through a unity gain buffer then go through a 2x Gain opamp stage to finally ...
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33 views

how emitter follower circuit works as a level translator? [closed]

this question is with the reference to u working of level translator stage in op-amp.Because direct coupling is used, the dc voltage level at the output of intermediate stage is well above ground ...
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22 views

Please help me to solve this problem op amplifier is ideal bode plot [closed]

[![enter image description here][1]][1] [1]: http://i.stack.imgur.com/ms14B.jpg solve this problem op amp
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2answers
66 views

Do I need isolation for op-amp stages in a current pump circuit like this?

U3A (OPA703) is used to shift a unipolar DAC signal down to a bipolar signal and feed it to U1 (OPA544). The OPA544 takes this bipolar signal and produce a pretty high current of about 3 Amps at the ...
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74 views

inverting op amp with a load resistor

what is the impact of a resistor when it is connected to the output terminal of an inverting amplifier. Does it make any difference to the output voltage or to the gain?
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61 views

Does audio OP-AMP circuit needs output capacitors?

I saw schematics with and without output capacitors. So in the end - do you really need capacitors in the output? I am using OPA2134 operational amplifier. I plan to use it both as headphone and ...
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75 views

LiFePO4 Constant Current charging circuit with micro controller

I made a small off-grid solar station a few years ago, that was relying on lead acid batteries. I am now planning to change it for a 12v 8Ah LiFePO4 battery, because of it's low weight, space needed, ...
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2answers
161 views

comparator sending out vcc value

I am having trouble using an comparator, the LM319N. I am trying to get a 0.5V to -0.5V signal to raise to a 3.3V - 0V signal so i can read it using gpio pins on my micro controller. I tried a few ...
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1answer
86 views

Do i need add a capacitor on this current follower?

Hi,guys. I am making a current follower. I want to know the difference between the circuit with and without that capacitor.(I forget to change the value of each component, just ignore that).
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93 views

LM393N output doesn't behave as expected

I am currently working with the LM393N and am inconsistently getting a high output when it should be low. Below is a schematic showing the inputs and outputs of the IC. VCC is coming from a "12V" ...
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1answer
81 views

AGC with multiple op-amps

I have four op-amps that are each amplifying signals from four different microphones. All of the microphones are recording a single source, but the location of the source moves, so the outputs from ...
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2answers
266 views

Removing offset due to PNP output

Below is the complete circuit for a PWM control output: (please left-click to enlarge) "Out" in the schematics will be directly connected to PWM input of a 3-wire or 4-wire DC fan. Since I don't ...
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1answer
75 views

Open-loop gain of Op-amp - LT6015

I was recently reading a technical article from AllAboutCircuits by Robert Keim about Op-amp Stability, http://www.allaboutcircuits.com/technical-articles/negative-feedback-part-8-analyzing-...
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1answer
101 views

Op amp Discrepancy

I am using an OPA241PA op amp to amplify a variety of voltages (around 0.6-3.3V input to about 4-23V output). If I have understood the datasheet correctly, this amp should be capable of accomplishing ...
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6answers
623 views

How to understand the open-loop gain of a op-amp?

According to the book Electrical Engineering 101, the open-loop gain of an op-amp can be very high, say 5000. When the difference of the 2 inputs is 1V, the calculated output can be as high as 5000V. ...
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73 views

Opamp phase shift compenation

I have this circuit using TL064IN OPAMP to amplify a 50Hz signal two times with different gains, the two output signals has to be in phase with each other. The problem is when I did the simulation to ...
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66 views

Right leg driver in an instrumentation amp?

My two groupmates and I are currently rereading a report on a project of ours, and having a bit of trouble regarding the theory behind something we did. In the project we designed an EEG machine, ...
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4answers
357 views

Op Amp in buffer configuration is decreasing output voltage

I have a 4.24V DC signal which I have to apply a buffer in the purpose of have a high impedance between the 5V signal and Op Amp output. My circuit is like following: The problem is that my output ...
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2answers
72 views

viability of idea for low voltage signal clipping (distortion) for guitar effect

I want to create an guitar distortion effect. What I want is a unity gain buffer op-amp that clips the signal. In the drawing below there is a circuit found on this forum here which will clip a very ...
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107 views

Level shifting pedal output to 0-5V

I have an accelerator pedal which outputs .75 to 4 V and I need to convert this to a 0-5 V output for my controller.I found a circuit that fits(shown below),which uses an opamp in non-inverting ...
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62 views

Convert a dual supply op amp circuit to single supply

I have made a dual supply circuit as above. This circuit is a variation of Howland current pump. The circuit output (at R18) is connected to battery pack of 6.5 Volts and the pack negative terminal is ...
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1k views

Equal voltage, but not shorted?

This is a fundamental circuit question. Suppose two nodes of a circuit are always kept at the same voltage by some unknown mechanism. If I now connect these two nodes with a wire, would it introduce ...
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1answer
94 views

Choose DAC for audio

I am trying to play music from a PIC microcontroller using a DAC. I have seen other similar questions, but they use parallel interfaces and I am hoping to save pins with SPI as the interface. I saw ...
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1answer
79 views

Vout of differential amplifier as Vref of comparator

simulate this circuit – Schematic created using CircuitLab I am a beginner at circuit design, and I am having trouble using the Vout of differential amplifier as Vref of comparator. The other ...
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1answer
90 views

What is the role of the resistor at the input of the OpAmp? [duplicate]

Could anyone explain the role of resistor R1 in the circuit below? Thank you.
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1answer
27 views

MC34072 maximum drawn current

How much current can this MC34072 op-amp deliver on the output? Not 100% sure on where to find it in the datasheet.. But is it on page 11 in the pdf document, where the graph shows supply current vs ...
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285 views

Why isn't this opamp working correctly?

I am working on an adjustable current source. In a thread awhile back, various circuits were discussed: simple adjustable current source for LED string ... but as I have settled on one option, and ...
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83 views

Current Amplifier using bjt [duplicate]

The output current through V5 is supposed to be 1A and I am getting around 460μA. TIP122 and TIP127 have minimum current gain of 1000. So the current entering each darlington transistor should be ...
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39 views

The equation op amp output impedance

Tell me please. How to describe the dependence of the equation output impedance AD8510.
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3answers
147 views

Measuring the bode plot of an op-amp circuit

So a few weeks ago I had to do an experiment and one of the exercises was to measure the bode plot of an op-amp. The instructions told us to measure the voltage and phase difference at the points \$...
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1answer
61 views

Oscillations in Precision Voltage to Current Converter Design

I am trying to re-design the TI Precision Design - Low Level (5uA) V-to-I Converter. My design goals are: Increase bandwidth from around 1kHz to 100kHz (ideally 1MHz in the future) Increase output ...
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1answer
127 views

Solution for adding around 60V dc-offset on digital signal(0 and 5v) of 10MHz frequency

I thought of using Opamp adder for this but the problem is high offset value which can saturate the Opamp. Can you please suggest some other solution ?
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1answer
87 views

Voltage to current converter

In the circuit diagram, R11 is the DUT across which current needs to be measured. According to tests performed on the device, the output current is 1A for sinusoidal input of amplitude 10V and ...
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27 views

How to use Op-Amp circuitry to measure voltage across Power rail?

How to use Op-Amp circuitry to measure voltage across Power rail? I would like to measure or Make sure +18V external input supply is correct or not before enable switching +18V power to on board ...
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77 views

How sine wave is generated in wien bridge oscillator? [closed]

It is known that the initial feedback signal is developed from the noise in the resitors and the transients of the power supply. The question here is : why the waveform at the output is sine wave ...
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56 views

Limiting Output Voltage of the Opamp-to avoid saturation

Problem: my photo diode recieves pulses of width 10ns-150ns and repeating at rate of 1Hz-50KHz the current from photo diode depending on incident light can go from 10nA-100mA, in a nutshell, my ...
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4answers
124 views

What happens after opamp saturates

here below is a TIA stage intended to do I-V conversion, as the maximum supply voltage being 5V for a given feedback resistance of 1K the opamp would saturate for a input current from photo diode of ...
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1answer
63 views

Measuring opamp output voltage (with virtual ground) on arduino

I have been working on a simple project to read the analog voltage input on Arduino. I'm having problem to read the correct value on Arduino. I know what's causing the problem. I'm using the virtual ...
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1answer
70 views

OpAmp circuit with diodes: conduction conditions

Consider the circuit below, where \$\ v_2\$ is an arbitrary input voltage and not necessarily equal to 3V as in the image. Both diodes and the OpAmp are ideal. If only diode 1 is conducting or if ...
3
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1answer
60 views

Relaxation oscillator with two time constants

I have the following circuit and I have to find the duty cycle of the output signal and its frequency: I figured out that if \$v_{cond} > 0\$, then D4 will be forward biased and D3 reverse ...
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1answer
213 views

Is it possible to use an opamp to generate 13V VPP for ICSP?

I have used a 34063 DC boost converter to generate a 13V VPP voltage for a PIC ICSP programmer, but would it be possible to use an opamp instead? The circuit pictured below seems to generate 13V (...
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1answer
53 views

Class B power amplifier using only Nch FETs

I'm building a combined linear regulator/electronic load. When the output is lower than the supply Q3 acts as a linear regulator and when the load tries to pump power back the other way, Q6 acts like ...
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1answer
37 views

Difference amplifier with current output error budget

I stumpled over the following article comparing the following difference amplifier circuits in terms of errors due to input offset voltage and resistor tolerances. To my understanding the right-...
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42 views

Weird op-amp voltage increase when using AC-DC power supply

I'm trying to create a PWM signal to dim an LED. I came a across this circuit: When I tried it out on a breadboard powered by a 5v supply coming from my USB Digilent Analog Discovery, it worked great....