Skip to main content

Questions tagged [operational-amplifier]

Questions relating to the construction and applications of operational amplifiers, which are DC-coupled, high-gain electronic voltage amplifiers with a differential input and, usually, a single-ended output.

Filter by
Sorted by
Tagged with
0 votes
1 answer
86 views

How are opamp node voltages being set in the following circuit and what is the use of the diode configuration?

I am using a PCB which has the following opamp configuration implemented. It's supposed to be a precision buffer for the source V3. I accidentally connected the source V4 as well and observed strange ...
0 votes
1 answer
150 views

OP-Amp 564 Output Shutdown

I need to build a controllable output shutdown for the OPA 564 so I can force the amp to shut down. The solution in the datasheet uses an optocoupler but I rather use it with some pull-down resistor. ...
6 votes
4 answers
6k views

Operating principles of a sawtooth wave generator bootstrap circuit

In one of my assignments, I was asked to explain the working principles of the sawtooth wave generator shown below. The input voltage is a spiked waveform obtained from a differentiator circuit. I ...
4 votes
3 answers
474 views

Issues with ICL7660 ICs from eBay - Overheating and Failure

I recently purchased several cheap ICL7660 ICs from eBay to use in an OpAmp circuit. Unfortunately, I've encountered issues with these components, specifically overheating and subsequent failure. Here ...
0 votes
1 answer
151 views

What should be preamp gain so output is at line level?

this is the MIC spec: PREAMP I'm planning has a gain of 100: I feel that gain of 100 is too much for a line level output. What should be correct gain? Thanks!
0 votes
2 answers
81 views

What is the maximum dBu I can send into a microphone input in this schematic?

The schematic below is from the Icom 9700 radio service manual (page 80). I would like to feed this input from a mixer board's ALT-3/4 outputs, and I want to avoid blowing the TS462 microphone preamp ...
0 votes
1 answer
162 views

How to compensate an op-amp at a particular frequency?

I am trying to design an op-amp but because it is going to be used at a max frequency of 10kHz, I only need to make sure the phase margin is good enough at this frequency. Most of the methods for ...
0 votes
2 answers
163 views

distance between linear and non-linear function of op-amp system

I have a circuit which I have taken a picture of as you can see, in which i have values of $$R1=1k\Omega,R2=10k\Omega,R3=10k\Omega.R4=10k\Omega,R5=20k\Omega$$ and sine input signal with off-set value=...
-4 votes
0 answers
43 views

Draw circuit using OPAMP [closed]

Draw circuit using OPAMP to implement formula Vout = Gain x (V1-V2) where Vout should be limited within +12V and -5V using Zener diode, Power supply to OPAMP is +15V DC and -15V DC
0 votes
1 answer
61 views

Part name of this IC - "LLA#537"

I want to know the part numbers of the components marked as shown in the attached image.
-1 votes
0 answers
55 views

Can you help me understand this transient output of this universal biquad filter? My Bode plot proves that the filter is working perfectly [closed]

I am designing a universal biquad filter in LTSpice and ASLK Pro board with a square wave input: I have taken the Q factor as 1. I'm not convinced it is right. Is it as simple as the ratio of RQ/R6?...
4 votes
1 answer
185 views

Part name of this IC - Analog Devices, 8-pin, "S 6B" A 06" "C 42"

I want to know the part numbers of the components marked as shown in the attached image.
1 vote
0 answers
50 views

Need help analyzing sability of op-amp in a current source in LTSpice

I have to perform stability analysis on an op-amp (AD8671) which is being used as an op-amp in the circuit attached. I am using LTSpice to perform this. My approach is to give a 1V AC small signal at ...
-1 votes
2 answers
163 views

How will the output of an op-amp such as the LM741 be biased?

I have been working with integrated design. Now I am working on a discrete circuit design project. I want to understand how the bias at the input will change the operating point at the output of an op-...
-1 votes
2 answers
66 views

Opamp inverting and non inverting issue

I want to get inverting and non inverting square wave at the same time. I am using EL2444 quad op amp, gain not required. My input is approx. 550 kHz, 50% duty cycle square wave. I assume that I will ...
6 votes
5 answers
2k views

What is the purpose of the BJT in this circuit? [closed]

What is the purpose of Q1? Is it just to amplify the current? What region will Q1 be operating in and how do I determine this?
-1 votes
0 answers
42 views

Opamp with Mosfet [closed]

I had a problem in designing the following circuit in pspice. I wanted to know how much Vbise, CL, and Cc should be, and is the output of the circuit at the location specified in the figure?
1 vote
1 answer
153 views

Can I use op-amp together with PCM5102A?

Is it possible to use op-amp with PCM5102A? In my application the load is much lower than 10k, so as a result I have much lower Vrms than it's defined in the data-sheet (2.1V). Maybe it's possible to ...
6 votes
2 answers
2k views

If there exists a cascade of op amps, does the previous op amp's slew rate affect the later op amp's slew rates?

All op amps used are the same Texas Instrument LM348n. The datasheet says the op amp has a nominal slew rate of 0.5 V/µs, but gives no tolerance. I have a square signal with an amplitude of 500 mV ...
0 votes
0 answers
38 views

PCB track widths for optimized layout for operational amplifiers

When designing a PCB track, its width, length, and stack-up can introduce inherent inductance and capacitance. These parasitic elements can significantly impact the performance of sensitive circuits, ...
1 vote
2 answers
155 views

How do I find the closed loop output impedance of an op-amp in terms of R,L,C parameters?

How do I model the closed loop output impedance of an op-amp with R,L,C parameters? Is there a definite method using simulations? And is it possible to relate it with individual transistor ...
0 votes
2 answers
165 views

Am I overloading my circuit?

I'm using op-amps as schmitt trigger and with the resistors in the wheatstone bridge I am trying to control the flow of current in the load. When the load resistance is not connect between the outputs ...
2 votes
1 answer
126 views

About the vout of a different opamp circuit

I greet everyone in the community, While trying to solve such an opamp circuit on paper, I could not find the formulation, I simulated it, but I could not find the value in the simulation. I find ...
2 votes
1 answer
61 views

port 7 and port 4 in the opamp that I can't make sense of

I greet everyone in the community, I have a sample circuit like this and this is how I simulate it. theoretically X and B values on paper; X = 1.5 VOLT B = 3 VOLT as But in the simulation I find the ...
3 votes
2 answers
88 views

Related to the opamp question solution (a point I don't understand in the difference amplifier)

I greet everyone, I am in the process of learning opamps, I got stuck here while solving a question about the difference amplifier. When finding the Vo value, we do the following operation; \$V_O = \...
-3 votes
0 answers
29 views

VLSI, multistage log amplifier with mosfet [closed]

How can we make multi stage log amplifier with mosfet? any reference?
0 votes
2 answers
178 views

I want to understand this circuit and these equations

I have a hard time understanding this circuit that I’ve been given because of the way it looks. I don’t know why, but electrical circuits seem very confusing to me even after reading the chapters to ...
0 votes
0 answers
33 views

How would one find the currents and voltage drops in this ideal OP-AMP circuit? [closed]

The problem only states that it is an ideal OP-AMP, and calls to find Vc, i1, V2 and the voltage drop at the 5K ohm resistor, all while using Kirchoff's node law and OP-AMP constraints.
1 vote
1 answer
62 views

How would one calculate the transconductance of the FETs in this circuit?

I was given formulas to find the transconductance (gm) of the FETs using IDSS, VP and VGS, however, none of the ways I tried them leads to the correct answer (given as 2,55mS).
1 vote
1 answer
300 views

MCP6548 comparator circuit isn't working

Hey guys back at it again, sorry. I am using a standard MCP6548 Comparator to finish the first stage of my project. simulate this circuit – Schematic created using CircuitLab OP's schematic. ...
0 votes
1 answer
157 views

Two pulse to create one pulse circuit

I have two pulse quick outputting of an Op Amp at a particular voltage. What I am trying to do is have an output pulse to trigger at the first rising edge pulse and fall at the second rising edge ...
0 votes
0 answers
41 views

Op-Amp oscillations when controlling P-MOSFET Vgs

My background is digital design, I guess the answer is obvious for all here, but not for me. I am studying example of analog physical layer for USB 2 protocol which I found in this paper. Also ...
1 vote
2 answers
268 views

Solving complex opamp circuits

I'm having some troubles understanding how to solve complex circuits with opamps like the following: During my lab course (I'm a physics major) the professor showed us the solution of very simple ...
1 vote
1 answer
30 views

How to gemerate a square wave circuit with lower level at 20V and higher level at 40V with several DC power supplies

I would like to ask for help to build a circuit that is able to generate a square wave with a lower level of 20V for 1 ms and an upper level of 40V for 9 ms. It is quite challenging for me as it needs ...
1 vote
1 answer
158 views

Shutdown unipolar to bipolar op amp output

I'm building a board that converts a DAC 0 5 V output to -10 0 10 V output. As a reference for my design, I'm using TI paper SLAA869. I'm also using AD5663 as a 16-bit DAC, ADUM1300 for isolation, and ...
0 votes
1 answer
73 views

How to Properly Select Resistors and Capacitors for a Voltage Reference Circuit with BJTs

I am working on a reference voltage circuit and I am having trouble when selecting the appropriate resistor and capacitor values. The circuit involves OP07 operational amplifiers and transistors (...
0 votes
0 answers
15 views

AD8232/AD8233 not working for sEMG

I am working on an sEMG circuit using the AD8232 and cannot figure out what is going wrong, the circuit isn't outputting the correct signal when connected to the forearm. I am using the 3 lead ...
1 vote
1 answer
93 views

Why does this two stage op-amp not work?

I was trying to simulate a two stage op-amp I had just learned about. I am going step by step i.e. as you can see from the schematic I have started with ideal current sources. I know that this op-amp ...
1 vote
4 answers
97 views

Instrumentation amplifier input bias currents direction and error

I am trying to understand how the input bias currents flow in op amp and instrumentation amplifier circuits and what errors they create. I came across a circuit that looks like the following: ...
0 votes
1 answer
80 views

50 Hz 2.5 Vpk-pk signal amplification [closed]

I get a 49.8 Hz 2.5 Vpk-pk sine signal. I want to amplify this signal and drive a 22 Ω resistor. Do you have a chance to provide an example of amplifier circuit design? As a result of this upgrade, ...
1 vote
2 answers
173 views

Transimpedance amplifier with OPA838 - oscillation - supply voltage

This post is the continuation of my previous post: Transimpedance amplifier with OPA838 - instability Considering there were a lot of discussion, so we made this new post, to add for details, such as ...
0 votes
1 answer
173 views

What kind of op amp is it? how do I calculate the VA voltage?

the first value of Q1='0' (off). how can I calculate VA voltage, the output of op amp ? I am not sure if is it like a buffer cause I've never seen some buffer like this. thanks ahead for any help ...
2 votes
1 answer
86 views

Implementation of Circuit in AN104 for Load Transient Test

I have been testing the transient response of line regulator simply with a MOS and the resistor, this method, however, cannot generate arbitrary current and the current is not accurate. To improve the ...
0 votes
4 answers
397 views

How to shift/offset a AC signal

I have made the following circuit, that amplifies a 50mV RMS signal to 0 to 5V. The circuit has 2 2nd order LPF at unity gain and a 30dB (30 V/V) gain amplifier. Below is a circuit diagram: Input ...
0 votes
2 answers
186 views

Problem amplifying differential signal from DAC

I encountered a problem while designing my own waveform generator. In my design, I am using a DAC (DAC5662) to generate different types of signals, and then I amplify the signal using an operational ...
0 votes
3 answers
149 views

What is the difference amplifier common mode voltage?

In some sources it is stated that v1 is directly equal to Vcommon mode voltage in difference amplifier, but isn't Common mode voltage (V1)/2 as calculated?
-1 votes
1 answer
90 views

Chinese clone op amps , not talking about counterfeit / fake op amps [closed]

I already know about Chinese counterfeit / fake op amps, AKA getting a totally different op amp and re-etching the IC or faulty op amps going to china and these op amps getting sold. But what about ...
1 vote
1 answer
60 views

Transfer function of differential controller

I found an op amp circuit that is designed to be a derivative controller (D-controller) simulate this circuit – Schematic created using CircuitLab and the transfer function $$ \frac{V_o}{V_i} = ...
1 vote
1 answer
50 views

Voltage Divider + Unity Buffer as a power supply

I'm working on an application where I need to step down a 3.7V LiPo down to a 1.0-1.5V for an embedded device that takes AAs (effectively an AA-to-LiPo conversion kit). In order for "low battery&...
2 votes
1 answer
49 views

IRF540 MOSFET Replacement [closed]

I am looking for a drop-in replacement for an IRF540 MOSFET with a more robust transistor. I want to find a MOSFET with a larger, Safe Operating Area because it is the pass element in a linear 14-volt,...

1
2 3 4 5
171