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Questions tagged [inverting-amplifier]

Anything related to inverting amplifiers, i.e. amplifier circuits whose output is an amplified replica of the input but which exhibit a 180° additional phase shift.

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33 views

Single supply inverting OP amp. Problem: half signal at output

I have built a simple inverting amplifier circuit with LM4565 operational amplifier. But only half of the signal appears at the output of the circuit and the gain looks wrong as well. Could anyone ...
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1answer
44 views

Time constant of inverting amplifier, filter

simulate this circuit – Schematic created using CircuitLab I want to calculate the time constant τ of the filter. Can anybody help me?
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1answer
78 views

Can the output impedance on af op-amp be set to 50 ohm regardless of frequency?

I want to make a circuit with an output impedance of 50 ohms. I am dealing with negative photomultiplier tube pulses that in 50 ohm load look like in the picture below: I want to use the pulses to ...
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2answers
39 views

Finding Vout and Gain of a differential amplifier

I am given this figure below: And I am trying to find Vout and the gain. From looking at this source: https://www.electronics-tutorials.ws/opamp/opamp_5.html I have determined the gain to be 10k/1k ...
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3answers
309 views

Opamp stability given in not inverting configuration

If a datasheet (like AD828) says that an opamp is stable at Gain >2 (or reccomends to work with G>2, hence it is clearly not unity gain stable), what can we deduct about its stability in the inverting ...
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2answers
173 views

What is the difference between these two op-amp circuits?

I don't understand why when we design a proportional amplifier, the feedback has to be negative. When I run the simulation in simulink I get the same result for both circuits.
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36 views

What would be the difference in the voltage transfer curves of this two circuits, assuming the op-amps are not ideal?

How does the resistor connecting the non-inverting terminal to ground affect the transfer curve?
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1answer
101 views

How can Vo = A(V+ - V-), if V+=V-=0? [duplicate]

We’re considering an ideal opamp here; so does that mean that Vo is infinity ♾ * 0 (A * (V+ - V-))? Thanks!
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0answers
60 views

Simulating a specific MOSFET circuit in PSPICE

I want to simulate this circuit in PSPICE (to get approximate output waveform (\$v_o\$)) simulate this circuit – Schematic created using CircuitLab Here, \$v_{in}=0.2 \sin(wt) , \$ & ...
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1answer
37 views

Phase splitters/inverters using valves with directly-heated cathodes

I'm building an audio amplifier using Raytheon 6418 valves and I'm struggling with the phase splitter. The 6418 has a directly-heated cathode and I'm wondering what limitations this might introduce. ...
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3answers
57 views

zero AC gain of CMOS inverter

Why is the following AC analysis of CMOS inverter resulted in zero AC gain (vout/vin) ?
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1answer
82 views

What is function of the resistor in series with bypass capacitor in npn transistor amplifier?

I am new to electronics and recently I was learning about npn transistor as an amplifier. I tried to build one in ltspice XVII. This is my circuit diagram: but the output was not as expected as ...
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1answer
123 views

Op-amp problem, two inverting amplifiers?

So I stumbled across a rather strange ideal op-amp circuit that I've never encountered before. I've done enough problems regarding inverting amplifiers, non-inverting, summing, difference, and such, ...
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2answers
119 views

Inverted Pulse Generator

How to design a circuit (only using transistors) which takes 0V to 3.3V step at the input and generates a negative 1ms pulse at the output. ...
1
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1answer
58 views

Designing a Band Pass Filter

I need a band pass filter that only accepts frequencies from 1000 to 1400 Hz and then toggles the transistor. It has to work from .1 Vpp to 1 Vpp and rejects anything else. I have been testing this ...
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3answers
99 views

Inexplicable base bias

I have a common emitter amplifier on my breadboard (the same circuit as the image) with the following values: C = .01uF, R1 = R2=15k, RL = 5k, RE = 1k, and Vcc= 10v. The reason I have R1= R2 is I ...
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1answer
53 views

Unconnected Inverting terminal of op-amp to hold a steady voltage?

I recently completed my final for my first year electrical Engineering Subject and I have the image of the question above. I was really confused because it says when both switches are open, which ...
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4answers
175 views

Non-inverting output of transistor circuit (at NPN base) is 0.69V max. why?

I tried to make a simple NPN transistor inverter so that I can use the strobe line of the parallel port to store data in two separate flip-flop IC's. (74HC174 and 74HC574) The IC that data will be ...
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0answers
68 views

Convention of closed loop gain in op-amp for inverting configuration

I tried to analyze real op-amp equations, in inverting and non-inverting configurations. I found a reference question here in which they were calculating exactly what I wanted to do: calculating the ...
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2answers
115 views

How do I determine the purpose of this op-amp circuit?

I have this circuit and I was asked to determine V2=f(V1) and V3=f(V2) which I determined below. The next step is to figure out what the purpose of this circuit is but I'm not sure how to do it from ...
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1answer
119 views

LTC6994-2 signal inverted and time delayed

I use LTC6994-2 to delay and invert input signal. I want 2s delay between input and inverted output. However, this is what I get on the output: Green waveform is input waveform. Output (Blue ...
2
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1answer
86 views

OP Amp bridge - any warnings?

In order to double output voltage swing I was going to use two OPA548 in difference configuration, connected to opposite inputs like this: I had one big concern about this circuit - that ground-...
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2answers
119 views

Resistor in the inverting terminal of the op-amp

I was studying the gain of an op-amp in both inverting and non-inverting configuration. In case of inverting configuration, the resistor is in series with the applied AC voltage. But in case of non-...
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3answers
134 views

Single Suppy Opamp for inverting amplifier produce negative voltage signal

i made an inverting amplifier circuit using CA3130, the supply just the positive voltage and GND for V- supply. the circuit is used for full wave rectifier because the signal is around 1 MHz and 500 ...
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1answer
80 views

Canceling ambient sound [closed]

I've just moved into a new flat and I noticed that there is a lot of car noise coming through windows. I know, I could just close the windows, but that's a less interesting approach to a problem. So ...
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1answer
78 views

Noise Cancellation Project [closed]

I am working on a noise cancellation project and I am having problems with my design once I breadboard it and connect my 8ohm load. Design Notes: I am not applying/mixing any kind of signal into ...
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1answer
149 views

Design a circuit using 1 ideal op amp whose output is Vo = VI1 + 2Vi2 - 9VI3 + 4Vi4

So, I've been staring at this problem for several hours now. I've watched videos on summing amplifiers, and the like--but nothing seems to show how to use 1 op amp in a circuit that acts as both a non-...
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1answer
314 views

Problem with output swing in LM358

simulate this circuit – Schematic created using CircuitLab I am working on a battery charger with indicator. I am using a LM358 to compare the voltage of my battery with a reference voltage of ...
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3answers
1k views

Use of superposition principle for the inverting amplifier

My current understanding of the inverting amplifier goes as far as assuming the second golden rule: no current flows through the OpAmp. From here on, up to the end result of \$ H(\omega) = -\frac{R_2}...
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2answers
103 views

Calculating voltage at non-inverting input of the op-amp

I am asked to calculate the voltage at the non-inverting input of the op-amp if v1=4.78V and v2=0v. I thought that the answer would be zero, as the voltage at the non-inverting input must be ...
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2answers
84 views

Transfer function of Operational Amplifier

I am trying to solve the following operational amplifier circuit to get its transfer function. I have tried two different approaches, one is elementary approach by finding V- and V+ and equating ...
2
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3answers
84 views

Negative feedback sustainability

If positive feedback makes output exponentially increase and cause instability in an opamp then why doesn't negative feedback make output extremely small and cause the system to collapse?
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0answers
39 views

Shaping negative pulses to positive ones pt2 [duplicate]

I asked a questing a few weeks ago, and asked a follow up question as a answer to that post? Apparently that's not allowed, so I am making this post instead. The question is based on this thread: ...
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1answer
46 views

How to calculate the feedack resistor in this configuration

I try to simulate the input stage of the ADC feeding circuit. ADC is 0-3.3V. The circuit: The Vin input signal: The output: The signal is shifted properly but the gain is lower than I expected. ...
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1answer
140 views

Photodiode circuit Op Amp and amplification failure

I am trying to build a photodetector circuit to detect and amplify the output signal of a fiber laser. I started with testing my fiber pigtailed photodiode on a breadboard as shown. simulate this ...
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1answer
485 views

How to determine the input impedance of an inverting amplifier?

How do I determine the input impedance of the op amp in the given circuit? Mind you, the input impedance of the op-amp and not the circuit itself. I have data on the input voltage and the output ...
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1answer
389 views

Inverting schmitt trigger with pnp transistors

I have a question regarding Schmitt Trigger. I am trying to design an inverting output (at UTP=Low, at LTP=High) Schmitt Trigger for an application. However, I need to use PNP transistors since the ...
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2answers
399 views

Input Output Relationship of Inverting amplifier

Can someone explain the input output relationship of below attached image ?
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2answers
151 views

Transfer Curve of Amplifier

Can any one help me out to design a circuit with opAmp using this transfer curve? Here, OpAmps +V(sat) = 15v and -V(sat) = -15v
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3answers
250 views

4069 envelope follower

I am trying to build this envelope follower: And I haven't been able to get it to work. Without any inpt signal, I'm getting a constant voltage at pin 6 (just before the 1k resistor and LED) and even ...
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2answers
89 views

Opamp inverter with bias voltage on non-inverting input

I was reading the datasheet of TDC1000, an ultrasound front-end IC manufactured by Texas Instruments, and had a doubt regarding the biasing scheme (to VCOM) they use for the amplifiers in the Rx path. ...
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2answers
493 views

Resistor Between Voltage Reference and + Input of Op-Amp? Why?

something I commonly see in schematics which include op-amps set up as inverting amplifiers is the inclusion of a resistor between the non-inverting "(+)" input of an op-amp and a strong voltage ...
0
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1answer
284 views

Differential op amp to measure negative current flow through shunt (Rails set to 0 and 5v)

Note* I have done some searching and though there are related topics to this one, this one is unique and I think it warrants its own Question, especially as asking additional questions on another ...
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1answer
958 views

Phase Shift Of Operational Amplifier [duplicate]

From the datasheet the open loop phase shift is given as 90 degrees for a range of frequency. But why doesn't a a normal open loop inverting amplifier does not show this characteristics of the phase ...
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3answers
330 views

How an op-amp determines its output without a reference point? [duplicate]

I was struggling to understand how an op-amp determines its output without a reference point. The output of an op-amp is A * (Vni - Vi) Then let's say we have an inverting op-amp with a gain of 1000,...
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2answers
180 views

Solving all-pass using superposition

I was reading this document talking about the use of superposition with dependant sources. At example 14 they state the following : I don't understand how they pulled the equation for Vo by ...
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1answer
221 views

Inverting Amplifiers LM308

I was required to draw a schematic diagram of inverting amplifiers using LM308 Op-amp in LTSpice. I need to connect +ve power supply to 10V and -ve power supply to -10V, a feedback resistor of 10k ohm ...
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1answer
380 views

Impedance of an Electret Mic

I have an electret mic for the design of an audio amplifier using input and output stages. How can I measure the impedance of that mic?
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2answers
405 views

Calculating current in the inverting op-amp

Okay, so I know the "correct" way to calculate current. Let's first analyze the circuit: KVL left side: \$ -V_{in} + i_1 \cdot R_{in} + 0 = 0 \$ \$ V_{in} = i_1 \cdot R_{in} \$ KVL right side: \$...
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2answers
125 views

How to calculate the gain of the OP-AMP in this configuration

Sorry for my ignorance in this field but I have failed miserably trying to figure the gain of this circuit: simulate this circuit – Schematic created using CircuitLab Simulation shows that the ...