Questions tagged [photodiode]

A photodiode converts light to an electric current.

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30 views

How to connect photo diode to trans impedance amplifier?

transimpedance example here I need to design a trans-impedance amplifier to amplify the signal from a photodiode to make a PPG sensor I need a signal to acquire from the wrist. photodiode I am ...
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2answers
45 views

What options exist for a for low-latency (<1ms) photosensor?

I'm wanting to build a computer keyboard-to-display lag measuring tool using an Ardunio: User places the photosensor right-up to their computer monitor. User presses a button on the Ardunio. The ...
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13 views

Q-value in APD photodetector

I try to calculate the Q value of APD photodetector with these parameters: $$R \hspace{0.1in} (response) = 1$$ $$M \hspace{0.1in} (magnification) = 10$$ $$k \hspace{0.1in} (ionization \hspace{0.1in} ...
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2answers
56 views

Vs1838B break beam problem

So im using ESP32 to output 38khz 40% duty cycle wave to ir led and connecting a vs1838b on the other side. The vs1838b works as it outputs LOW when i send a signal from my remote. Anyways, after the ...
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1answer
33 views

Finding value of feedback capacitor in a photodiode amplifier

I am tasked with the objective to design a photoelectric sensor. Being very weak on amplifiers & control theory, I am working on the basics of op-amps. Following this reference design by TI, I ...
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2answers
78 views

Do we use any filter after photodiode?

In wireless communication, we use a matched filter to suppress out-of-signal-space noise. After this filtering we do sampling. Otherwise, the power of noise is infinite (practically very large). In ...
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1answer
45 views

High gain and high modulation frequency photodetectors [closed]

I have been reading more into the gain of a photodetector and how the system works. We are picking up extremely small signals and need to use a detector with a gain of around 1.0 × 10^7 but preferably ...
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2answers
80 views

How to correctly connect op-amp to ADC

I have a SiPM connected to an op amp and then ADC. Everything works great except I am just guessing at what values to choose for R2 and C1. What questions should I be answering in choosing the ...
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1answer
45 views

Photon Shot Noise and an Ideal Photodiode and Ideal Transimpedance Amplifier

Light hits an noiseless photodiode and transimpedance amplifier. The light has photon shot noise. If it is relevant, lets say that the light is monochromatic. The photodiode, amplifier, and any optics ...
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1answer
83 views

How to amplfy µA from a fast photodiode with a bandwith of 10GHz

I want to measure faint laserpulses with a step slope (Bandwidth 5-10GHz). I have a photodiode which produces a photocurrent of some µA. Now I need a transimpedance amplifier to convert it to at least ...
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86 views

How to properly connect IR photodiode

I encountered some problems with the signal from photodiode and don't know how to connect it effectively. Datasheet can be found here: https://www.marktechopto.com/pdf/products/datasheet/MTPD1346D-...
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4answers
286 views

Amplifying photodiode current with BJT transistor

I'm trying to develop a kind of light detector. To do that, I'm going to use a photodiode and a bjt transistor to amplify its current. I found a circuit in this tutorial: which explains how the ...
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3answers
152 views

Photodiode to opamp

I need to detect if a monomode fiber loop is intact. To that end, I have a laser diode emitting max 10 mW (adjustable) at 1310 nm. At the receiving end, there is a matched photodiode (Laserscom.com ...
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1answer
37 views

Is the charge accumulation linear in time for image sensors?

Reformulating the question: Does the rate of charge of the pixels photodiodes in an image sensor depends of the previous accumulated charge? The pixel sensor integrates light during a specific ...
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3answers
80 views

Transimpedance Amplifier and Photodiode for BFSK

I am working on my first transimpedence amplifier circuit and am having some trouble. I have am looking to reconstruct a BFSK signal modulated on an LED. The BFSK signal uses a 50kHz sine wave at 80mA ...
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1answer
96 views

Does this high-bandwidth transimpedance amplifier ring (Multisim)?

I designed a front-end for the S5972 high-speed photodiode. See the following schematic. In Multisim an AC sweep analysis gives the following Bode plot: 1. Is the presented front-end stable? If not, ...
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3answers
85 views

Infrared Sensor for drug detection [closed]

I saw that there has been a push to make a drug detector that can identify cannabis since it has been legalized. I was looking at mouser.com and found this ir sensor: https://www.mouser.com/...
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1answer
51 views

Photodiode not working in reverse bias

I'm using a photodiode module, model: coaxial InGaAs, Gtel. I set it in reverse bias with 5V and tested it with a laser but it doesn't give any output voltage. Unfortunately I don't know the laser ...
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2answers
56 views

Nor gate using photodiodes and transistors doesn't work correctly

I'm creating a circuit for a robot to avoid obstacles. It is created without using any ICs. When the robot meets an obstacle the LED (at the right side of the transistors) should be off because of ...
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2answers
97 views

Phototransistor amplifier

In the following picture: I have screenshotted a picture of the front end of a phototransistor receiver circuit from Electronic Gadgets for the Evil Genius. It appears to be a phototransistor-based ...
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2answers
59 views

Big photovoltaic current

A photovoltaic cell is just a photodiode connected to a resistor.Now if simulate this circuit – Schematic created using CircuitLab I put many photodiodes in series , this would create a bigger ...
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2answers
43 views

How to design a transimpedance amplifier that can adjust to large voltage swings?

I am making a photodiode sensor based on one show in the image below which I got from this research article. The problem I run into with my photodiode sensor is that variations in sunlight create ...
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0answers
63 views

How can I increase the distance of a photodiode

simulate this circuit – Schematic created using CircuitLab I wanted to make a fire detection system using a photodiode, comparator with potentiometer to adjust sensitivity, and an alarm circuit ...
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1answer
57 views

Photovoltaic cell creation

In order to create a photovoltaic cell all I need is a photodiode connected parallel to a capacitor right?
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1answer
113 views

Introducing SiPM Array to an Op-Amp

I'm working on a transimpedance amplifier circuit, but it appears that there are issues reading out a signal. The source is comprised of sixteen individual SiPMs in parallel with each other, ...
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1answer
161 views

mV difference not detected by LM741 opamp comparator

I've made this comparator circuit, it has a changing current going through the photodiode and when lighting changes sufficiently it should trigger a 5V signal at the opamp output terminal. When the ...
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1answer
69 views

OpAmp resistor to ground in feedback loop

I am currently tasked with improving the design of an electrometer unit. It was NOT designed by an electrical, and there are some questionable design practices. My question is concerning the first ...
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1answer
79 views

Transimpedance Amplifier for Photodiode with low Shunt-Resistance

I am designing a transimpedance amplifier to amplify the signal of a photodiode. I plan to use the IC ADA4350 (datasheet), it contains an Op-Amp and analog switches to select different feedback paths ...
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1answer
57 views

Convert a Dusk-to-dawn outlet device to Dawn-To-Dusk? [closed]

I recently purchased a Dusk-to-dawn outlet sensor (https://www.amazon.com/dp/B00002NB2X?ref_=pe_2640190_261118450_302_E_DDE_dt_1), but I'm wanting to convert this thing into a Dawn-to-Dusk device ...
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38 views

Read BPW21R photodiode

I want to sample the output of a BPW21R photodiode Datasheet. I intend to use an Arduino. If the resolution is not good enough for the Arduino analog input pin (A0) Arduino Tutorial then I want to ...
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1answer
69 views

Help identifying a photodiode pre-amp PCB

Recently I found this PCB in a electronics junk bin. It's said that it's a photodiode preamp, but I was not able to find the datasheet or any information about the board. Since the PCB looks neatly ...
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1answer
43 views

How to connect/use BPRV2125AM?

We want to know how exactly do we make the connections of the photodetector since they are so fragile.Can we do a PCB, and if so is there any IC base for it.How do we work the RF output as we need to ...
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2answers
69 views

Hand contacting op amp photodiode circuit causes interference - what ist the physic behind it?

I am new to analogue electronics and I am still learning about op-amps. I use the most common circuit for amplifying a photodiode's signal to measure it with an ADC: Amplification gain is 1M, the ...
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5answers
83 views

LED and Photodiode Data Acquirement System

So I am to develop a project this semester and wanted to be shed some light on certain topics. The goal of the project is the following: Detect a pendulum's period using an LED and a photodiode and it ...
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0answers
37 views

Total thermal noise of a photodetector connected to a spectrum analyzer

I connected a photodetector to a spectrum analyzer (SA) and observed the signal (i.e. noise) on the SA when there is no light hitting the detector. I noticed that when I set a low spectral resolution ...
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2answers
50 views

Transimpedance AMP, Active HPF, phototdiode (updated)

The original post is here Transimpedance AMP, Active HPF, phototransistor I decided to change back to a photodiode instead of a phototransistor since I have used one for a similar experiment in the ...
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1answer
62 views

Photodiodes: the “generation” mechanism behind photocurrent

Assume I use a photodiode under zero-bias (that is in photovoltaic mode). How/why can a current flow in this bias condition? As far as I have understood the working principle of photodiodes, when ...
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0answers
63 views

Transimpedance AMP, Active HPF, phototransistor

So this is the part where I would like the phototransistor (TEMT6000X01) to be able to clearly capture an LED with a frequency flashing on and off at 1kHz. So what I have here is a transimpedance ...
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1answer
197 views

I have made a photodiode circuit and measured using multimeter - still no change in voltage. What to do? [closed]

My photodiode is MTPD1346D-100 (InGaAs PIN photodiode.) What is the photodiode input voltage? This is my circuit schematic:
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104 views

Photon count with ADC, am I doing it right?

I have this LED and I want to characterize this photodiode. The LED should produce light of 370 nm, but I measured it and it is around 358 nm, and at that wavelength the quantum efficiency (\$\eta\$) ...
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2answers
213 views

Simple Op Amp Non-inverting Amplifier Circuit Not Working

I am only just starting to learn about circuits and electricity, so please bare with me. I am attempting to build the circuit pictured below: And this is my rendition of it: Here are the parts used:...
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2answers
118 views

Switching multiple photodiode inputs to an op amp

I am playing around with LEDs as (semi)wavelength selective photodetectors and have reproduced the circuit found in Forest Mims' Make article: I have an operational circuit using an LM358 powered by ...
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1answer
171 views

Photodiode to an ADC

Please bear with me as I'm not too experienced with this. I'm attempting to use an ADC to get readings from a photodiode. From what I understand, I should likely use an op-amp as the range of the ...
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5answers
2k views

Thin wall to block LED light from hitting photodiode?

I'm designing a small heart rate sensor using green smd LEDs and a photodiode. The photodiode needs to measure the reflected light, and not direct light from the LEDs. The LEDs are near the perimeter ...
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1answer
27 views

How are solar spectra simulators used and are they used to test photo-diodes and image sensors?

For example here is link to a Xenon lamp solar spectra simulator Xenon lamp AAA Class Solar Simulator. Two spectra are shown in the plot given in the link, one for the AM1.5G reference an other of ...
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1answer
112 views

Photodiode showing triangle waves instead of square? (re: need op amp?)

I'm trying to visualize an infrared signal using a IR receiver diode but my oscilloscope is showing triangle waves instead of square for the carrier frequency: One of the guys at EEVblog said I need ...
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1answer
187 views

Using an IR diode as an emitter and receiver?

At the recent Maker Faire Berlin, I was told that LEDs can be repurposed as photo diodes. I assume the same is true in the infrared range. This sounds like a nice solution for building a transmitter. ...
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0answers
171 views

PIN Photodiode gamma detection amplifier circuit - rectangular wave output

I've been working on a project recently, where I need to build a device which detects gamma radiation and can be used for gamma spectroscopy. I've done some research and found many interesting ways of ...
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60 views

Troubleshooting op-amp circuit and compactor for buzzer

I tried building a radiation detector (cheap photodiode Geiger counter) on perfboard: http://opengeiger.de/StuttgarterGeigerleThruHole_en.pdf More details here. With the circuit was turned on, ...
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1answer
21 views

Relation for the current generated by a photo-diode in photo-conductive mode

If a photodiode with responsivity R is operated in photo-conductive mode with reverse bias voltage Vb and load resistance Rld what relation gives the output current from the photo-diode flowing ...

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