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.
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Right transimpedence amplifier choice for input range
I have a device that produces a ±30 nA signal and I'd like to measure this to a 0.1 nA precision.
Since the currents are so low and I don't have much time to make mistakes, I am planning to use a TIA ...
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How to Place the AC-coupling capacitance and resistance in a TIA circuit
I am planning to use OPA858 as the Transimpedance Amplifier for the following TIA circuit. C2， R8 are to AC couple the circuit: In the data sheet of OPA858, it recommends using this layout with Riso ...
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Putting a RC filter after the photo-diode to AC-couple the TIA gain stage
I have been designing a photo-diode circuit which separates out DC and AC signal of the photodiode. I am using MAX4007 as the current mirror for the DC branch and I am using OPA858 as the ...
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Determine feedback capacitor values for transimpedance amplifier
I need to decide feedback capacitance Cf for the for transimpedance amplifier. I have the confusion. Which equation is appropriate for finding the Cf?
Cf= 1/(2piRf*fp), where fp is the frequency enter ...
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how to measure leakage current across a zener diode with a transimpedance op amp
I am trying to measure the leakage current of a SMF36CA zener diode. I am doing this with a transimpedance op amp (LMC6062IM/NOPB).
Attached is the circuit I am using. The amp and diode in the circuit ...
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Transistor transimpedance amp design for photodiode digital input to arduino at 1MHz
I would like to use a photodiode with an atmega328 to detect pulses of light from a toothed disk (illuminated by IR from the far side) at around 1MHz. Its to detect mechanical jitter in the rotation ...
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Transimpedance Amplifier Not Outputting Voltage
I'm trying to build a transimpedance amplifier to convert the current from my photodiode to a voltage that can be read using an ESP32. The components I am using are:
OPA170AIDRLT Operational ...
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Would more connectors introduce more noise for low-frequency current signal?
General question
When measuring the weak amplitute low-frequency (DC) current signal (in 0.1 - 1 uA) transmitted through FFC cable and connectors to a PCB with transimpedance amplifier (TIA) and ADC, ...
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IR LED and Photodiode (G10899-01k) to make NIR sensor
I am working on a final project to detect glucose. I am using IR LED of 1200nm spectral wavelength and a photodiode (G10899-01k) of 500nm to 1700nm spectral range.
I have used a transimpedance ...
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Cannot Find MOSFET Transconductance - Incredibly Confused
I am tasked to find the gain of this small signal circuit drawn in my work. I have absolutely, NO idea how the professor came up with his answer. I would e-mail him, but he doesn't respond on weekends....
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What are the pros and cons for the various photodiode circuit arrangements?
I've been messing around with photodiodes do measure relative light intensity from very low light to very bright conditions. My search for information on photodiodes and the circuits they are ...
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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?
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BPW34 Photodiode TIA amplifier
I have a problem with circuit, for some reason I always have 4.8 volt in output.
Like a:
4.8 V - when I put finger on photodiode
4.83 V - in room light
8.27 V - when I light it with IR laser
What am ...
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Low gain transimpedance amplifier
I have an op-amp based current-to-voltage converter, where the input current is summed from a number of LM13700 OTA's. The signal is audio, so the bandwidth of interest is up to \$20\mathrm{kHz}\$. ...
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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 ...
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Transimpedence amplifier with photo-transistor linearity
Given that the irradiance and collector current for a (random) photo-transistor is linearly correlated like below.
Then I am wondering why the output voltage graph of the transimpedence amplifier ...
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Voltage output range of PSD circuit
I saw this circuit the other day on here: What is the basic circuit to wire up a position-sensitive detector, or PSD?
From what I understand from the answer given, the voltages X1 and X2 can be used ...
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T-network feedback of op amp [duplicate]
I want to know how the equivalent resistance of T network feedback in this op amp configuration is calculated?
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Transimpedance amplifier resistor calculations
How are the values of resistors in this transimpedance amplifier calculated? Also, why is a resistor divider used in the feedback path?
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Feasibility of high-speed omnidirectional communication through infrared light
I am currently working on the design of a low-cost communication system based on IR LEDs and photodiodes for my research project. The goal is to transmit data with ~100ns pulses across ~0.5m distance (...
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Input bias current calculation
I have a VBP104FAS connected as above with the LMP7721 opamp to produce an output voltage from the photodiode's small input current. I am trying to calculate the input bias current I need as I am ...
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Transimpedance amplifier circuit with uniform light input gives a sine wave output
I am trying to build a transimpedance amplifier circuit on a PCB (as in the figure below).
Although I have run a SPICE simulation and got the desired results, I wanted to test it out on a breadboard ...
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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 ...
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Can very small currents be accurately measured using only standard analog electronic components on an IC? [closed]
Let's say, for example, that I have a photodiode, which produces electrons in response to the amount of light.
What is the theoretical lower limit that can be accurately measured only using basic ...
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Designing a guard ring for a transimpedance amplifier
I am at that stage of a PCB design where I need some guidance on guard rings.
The Application:
The application is a photodiode circuitry (using a pin photodiode and transimpedance amplifier.) The ...
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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?
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Photodiode circuit unstable measurements on MCU ADC [closed]
I'm working on a fluoresce detection circuit. I have a lot of unstable measurements on the output of my second amplifier with the ADC. With the multimeter I have stable measurements.
How can I smooth ...
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Measuring <10 pA of photocurrent using transimpedance amplifier
I am working on a project that measures low intensity light.
The photodiode I am using an OSD35-5T. This is a large surface area photodiode. The idea is that the large surface area would absorb/...
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Feedback resistor and capacitor calculation for transimpedance amplifier
I am designing a transimpedance amplifier using LTC6268-10 from Analog Devices. The photodiode that I use is S9055-01 from Hamamatsu and the laser source that I use has a power of 10mW with the ...
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Photodiode Current Calculation for Simulation
I am designing a transimpedance amplifier and was trying to simulate the circuit to study its characteristics. I came across this online design tool provided by Analog Devices that builds the ...
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Is this a transimpedance amplifier?
Help needed on the below image: is this considered a transimpedance amplifier?
With the Vo of 3 V given, can I find out the current source current? Since this current source from 0:255 μA (28 bits), ...
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Current sense resistor vs transimpedance amp vs hall effect current sensor for instrumentation?
I'm using a photomultiplier tube; this creates a current output relative to the number of photons incident to it, on the magnitude of microamps. So, I need a precise and accurate way of measuring very ...
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High frequency photodiode laser receiver strange output
We've built this transimpedance amplifier circuit to receive 10kHz pulses from a laser. The laser is driven by a square wave signal generator and is pulsing correctly. We expected to see a square wave ...
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Understanding noise in transimpedance amplifier
So I've been studying on TIAs for the last days and understood everything except the term of "noise".
Let's take this TIA as an example: https://www.ti.com/lit/ds/symlink/opa380.pdf?ts=...
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Benefits of Transimpedance amplifier with a non-ground reference
Regarding this question -> Transimpedance amplifier with a non-ground reference
What are the benefits of having an ideal absolute static reference voltage instead of just simple GND on the non-...
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Transimpedance and resistor bias in IR transmitter
I've been studying the optical (photo-diode) transmitter and receiver circuit for a while. There's a case that I can't understand the difference. In the optical receiver bias circuit, what is the ...
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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 ...
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Multi stage & gain opamp output voltage issue
I am currently facing an issue with an opamp circuit.
The design consists of a transimpedance amplifier followed by a buffer stage and then followed by 6 non inverting gain stages (each stage 4 times ...
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Weird DC Response in Photodiode TIA Circuit
I'm building a photodetector circuit designed to measure the amplitude of a 1 kHz signal.
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I have reworked the feedback resistor (R2) to 383 kΩ and changed the bandpass filter to have a gain of 15.
I ...
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What is the equation relating Vin and Vout on a 2-Port Network?
I was reviewing a paper, and I got stuck while trying to understand the analysis of the two-port network.
This is the circuit below with the equation below it
This is my attempt below, my knowledge ...
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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 ...
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Current feedback amplifier
I was wondering whether is it ok to connect a current feedback amplifier (CFA) after the TIA stage to obtain high swing and large bandwidth. I am not sure how to connect the CFA after the TIA stage.
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Calculate intensity from a photodiode using voltage
I am running a photodiode through an op-amp circuit (trans-impedance amplifier.) I have been told I should characterize this device. I'm assuming he means using the voltage I get at a given distance ...
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Is there a current-to-voltage converter circuit for professional applications?
We want to measure the information from three sensors that generate current (4mA for the minimum value and 20 mA for the maximum).
Obviously, a simple solution could be to use the classic current-to-...
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Transimpedance amplifier design advice
I'm working on a transimpedance amplifier for a phototransistor in order to create a sensor that counts objects falling down a pipe.
This is the sensor: https://www.digikey.it/short/0vq01q7h
Datasheet:...
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Current to voltage circuit
I'm currently doing a project that consists of testing bio-implants to see if they are still good to use.
For this, I have to measure the impedance of the implant from frequency starting at 10Hz to ...
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Small feedback capacitor in photodiode amplifier
I'm designing a transimpedence circuit with a photodiode.
Op-amp: LTC6268 (GBW = 500MHz)
Photodiode: SFH2700 A1 (C_j = 4.6pF, max current = 1.5uA)
Required bandwidth: 2MHz
Using the calculation from ...
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Transimpedance amplifier transient voltage issue
We have below transimpedance amplifier, I have below issues, would like to know if this is even fixable or could be reduced:
When a large load turn on in main power supply of TLE2426 turns on cause ...
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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 ...
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transimpedance amplifier configuration in a polygraph circuit
I am working through an assignment to design a polygraph circuit which works off skin resistance and in the brief, it specifies that a transimpedance amplifier must be used. I have never used one of ...