Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [transimpedance]

The transimpedance of a device relates the current through the input of the device to the voltage across the output of the device.

The transimpedance of a device relates the current through the input of the device to the voltage across the output of the device. The SI unit of transimpedance is the ohm.

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What is transimpedance?

I've googled almost 100 times, unable to find what transimpedance really is. Every search displayed results about transimpedance amplifiers, but didn't explain the term transimpedance.
cipher
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Transimpedance amplifier for very low currents

I am currently working on a project, which requires me to measure the very low currents (approximately in the range of 100 pA to 10 uA) from an electrochemical sensor. The sensor is kind of a new approach and it is still in development at the…
Rata
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Why does using a second analog switch reduce gain error?

From the analog website this switchable gain amplifier is shown. It uses a second switch S2 to reduce gain error from S1's on resistance. Why is this the case?
W30
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Low noise transimpedance amplifier (TIA) - why does the addition of a feedback capacitor cause voltage noise peaking?

I am working on a low noise transimpedance amplifier (TIA) for the detection of weak optical signals. The aim is to achieve a 10MHz bandwidth with a white voltage noise floor of 10-20nV/rtHz. I am using the FGA21 photodiode and the OPA847 Op-Amp…
J-Pease
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Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?

I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer. Apologies for the quality... this is the best scan I could find. The design is furnished with the following explanation: In parallel with the basic…
Evan
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Reducing Transimpedance Amplifier Noise

I'm investigating a noisy output of a Femto DHPCA-100 high speed transimpedance amplifier. The final application is to amplify the signal of a PMT tube, but the bulk of the noise can be reproduced without the PMT. The test setup is shown below. The…
Ian Bloomfield
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Norton op-amps advantages

I have been reading about Norton operational amplifiers, I got a good idea of how they work, even at the transistor level, I understand that difference current input = voltage output. What I have been having trouble with is finding out about the…
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Large dynamic range current sense 1uA - 100mA

I am looking at large dynamic circuits and came across an interesting project by ETH Zurich called the rocket logger - https://rocketlogger.ethz.ch/ I am a little confused by their current sensing principle for which they implement a low and high…
Hart22
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Wrong Sign in the Output of 80MHz Transimpedance Amplifier

I have recently built the following circuit for (homodyne) differential detection of optical laser pulses. In fact, I rebuilt the circuit from this paper with small deviations: simulate this circuit – Schematic created using CircuitLab You can find…
tozero
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Transimpedance amplifier with decompensated op amp

I am trying to tune a wideband transimpedance amplifier for maximum speed. I am experimenting with the OPA846 and OPA847 op amps which have large GBW but they are not unity gain stable with minimum noise gains of 7 and 12 respectively. The minimum…
DavidG25
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Sensitive Transimpedance Amplifier Oscillates

I built a sensitive transimpedance amplifier for a photodiode. Motivated by this question, I am attempting to push the limits on sensitivity. I have some experience with sensitive transimpedance amplifiers, 30+ years ago I built one at work with a…
Mattman944
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DC transimpedance amplifier feedback capacitor

I am designing a simple photodiode light sensor circuit. The circuit will use a transimpedance amplifier to generate a usable voltage from the light level detected by the photodiode. The most basic form of the circuit looks like this: However, many…
J.P.
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Photodiode bias in TIA?

When I see TIA schematics, I can see either the photodiode to GND or against VCC. What is the difference?
nowox
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Transimpedance (I to V) converter using op amp

I was reading about the I to V converter using an op-amp. Doesn't the addition of the \$R_{\text{L}}\$ resistor affect the \$I_{\text{R}}\$ current? Because the same current that flows through the feedback resistor would also flow through the…
user220456
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Programmable gain Transimpedance amplifier for 4-5 decade resistance measurement using Pulse voltage/current

As you can see from my previous question, I am trying to measure resistance within the range of 200k-60 ohms (around 4-5 decades). I will be using a pulse (5us pulse width and 50ns each rise and fall time) voltage source of 200mV (max) across the…
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