Questions tagged [unity-gain]

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2answers
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Expected and actual unity gain bandwidth LM324N

I have an LM324N configured as a unity gain voltage follower. The split rail power supply +/- 4.5V is provided using AA batteries. I am aware that better opamps exist, but this is for study purposes ...
3
votes
2answers
476 views

LM358 opamp unity gain cap

I'm using an LM358 op-amp for unity gain (feedback to V-). However, I'm getting some unexpected results. When Vin is from 0v - 3.75v, op-amp output is as expected 0 - 3.75v. However, when Vin is ...
3
votes
3answers
460 views

500V unity gain buffer

I am currently in the process of designing a high-voltage bias supply for use with an ionization chamber. The voltage source itself is taken care of however I need a unity buffer to drive the guard of ...
3
votes
1answer
693 views

Sine wave distortion in simple op-amp circuit- bypass capacitor?

I've built a simple unity-gain buffer op-amp circuit from the UCSB lab here, with a 12V power supply and a 1V, 1 kHz input sine wave. simulate this circuit – Schematic created using CircuitLab ...
2
votes
2answers
395 views

How do you use Gain Bandwidth Product to estimate bandwidth at different gains?

I was doing a question related to the dependence of op amps on frequency.This question is from 2nd year electrical engineering micro electronics by sedra smith. Here is the question: So there is a ...
2
votes
1answer
125 views

Unity Gain Phase Splitter- Why outputs have different voltages

I’m trying to calculate the values of the biasing resistors for this phase splitter circuit. (I know the actual values of the resistors, but I just wanted to manually work it out). When I made the ...
2
votes
1answer
317 views

Terminating unused unity-gain Unstable op-amp

I am trying to terminate the unused unity-gain unstable op-amp. I have tried to terminate it with the typical unity-gain stable configuration (http://www.maximintegrated.com/en/app-notes/index.mvp/id/...
2
votes
1answer
204 views

High freq OP-AMP voltage follower is ringing and is unstable

I try to design analog buffer for the 5MSPS STM32 ADC. I try to use TSH114IDT or CLC4007 opamps ( I need 8 in total). I have done so far: Tried the design below with or without some of the elements - ...
2
votes
2answers
851 views

Adding offset voltage to sensor signal

I have a pressure transducer outputting 0-5V which is sampled by an ADC with a 0.5V minimum input voltage. I need to offset the sensor output voltage by a fixed voltage of 0.5V. I've looked at an op ...
2
votes
1answer
987 views

Op-Amp with Voltage Controlled Gain and Unity DC Gain

I have a car seat motor that I am driving via PWM and am aiming to measure its position by counting the minor variations in voltage across a current sensing resistor attached to the low side of a FET ...
1
vote
2answers
555 views

Unity gain op amp gives static, incorrect output

I have the circuit shown here: where I'm using a switching regulator (not the linear 78xx shown) to provide me with 5V to power an Arduino and a little more circuitry that the Arduino is monitoring. ...
1
vote
0answers
65 views

Does a Microcontroller act as a Capacitive load or resistive?

I'm designing a unity gain buffer (IC MCP6002) and in the datasheet, it says that a small series resistor is required at the output, if the load is capacitive and is >100pF. The input of the buffer ...
1
vote
0answers
57 views

Unity Op amp Question Gain and Resistances

The Question asks what is the gain in dB and also what are the input and output resistances I know the gain is 1 so dB that would be equal to 0 dB But I am confused on how to find the input and ...
0
votes
1answer
257 views

Can any Op-Amp be used as a voltage follower(buffer)?

I have a square wave, to which I have to add a buffer. The Frequency of the square wave is around 10MHz. I am new to Op-Amps, but I have read that I need a high slew rate. Can I use any Op-Amp(with ...
0
votes
1answer
2k views

Practical Opamp integrator problem

The opamp has an unity gain of 1 MHz.So when the resistor in parallel acts a feedback to bias the opamp stable.So if not for the capacitor,the circuit would have been a inverting amplifier with gain ...
0
votes
2answers
87 views

How do parallel resistors and capacitors reduces frequency peaking in opamps?

I'm trying to understand a schematic from the front end of an analog discovery scope. It uses an AD8066 opamp, and has a resistor and capacitor in parallel on the inverting and non-inverting terminals....
0
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2answers
175 views

Opamp Voltage Follower Oscilates

I am trying to measure voltage across a 0.1R shunt resistor. When i measure voltage between input1 and input2 with multimeter i can see 10 mili volts. When i connect input1 to a voltage follower in ...
0
votes
1answer
139 views

Op-Amp for the 50MHz unity gain voltage

I have tried many different op-amps in many configurations. But almost always I am getting a very unstable configurations: https://youtube.com/watch?v=ybhDs-dw6j8 https://youtube.com/watch?v=...
0
votes
1answer
750 views

Unity Gain Op Amp Configuration: Stability?

I'm planning to use the ADA4610 in unity gain configuration as a current buffer for a high precision (16-bit) DAC chip. The chip is labeled as being stable in the unity gain configuration. I currently ...
0
votes
1answer
296 views

Follower current source?

I need advice on a problem I'm having I need a follower to transmit an AC signal into a low impedance load which is the cathode of a triode but I also need it to be an adjustable current source to ...
0
votes
1answer
103 views

Simple OP-AMP Frequency Response

In my textbook, there are two interrelated equations. 1. wb = wt / (1 + R2/R1) 2. wb = wt / Ao where ...
0
votes
0answers
2k views

Unity negative feedback controller, why does Gain K go on the numerator of the transfer function

I have a system G(s). It has no zeroes, but some poles. When applying unity negative feedback, with a static gain K, why does K remain on the numerator of my transfer function T(s) which describes ...
-2
votes
1answer
63 views

How does op-amp gain = 1 - error?

Please see attached image. How does the voltage gain end up being equivalent to Av = 1-error? Thanks