Questions tagged [photodiode]
A photodiode converts light to an electric current.
441
questions
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1answer
45 views
Why does the high reverse bias voltage in a PIN diode circuit not damage the op-amp?
In this circuit designed to measure high frequency light pulses, the 30V high voltage bias input has a direct connection to the inverting input of the op-amp, despite also being connected to the ...
2
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1answer
68 views
opt101 (photodiode) adjust voltage output
I'm using the popular OPT101 photodiode with 5V. How can I scale the output between 0 and 5V (or as close to that range as possible)? Now the output is ca 0-400mV (maximum is room light here).
I'm a ...
3
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1answer
60 views
Long distance required between photodetector and TIA
I have a circuit that incorporates a 40 channel InGaAs (IR) photodetector array (https://www.hamamatsu.com/eu/en/product/type/G8909-01/index.html). I have a TIA design using a LTC6268-10 first stage. ...
1
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1answer
30 views
Please explain negative bias and “a stronger field to sweep carriers out of depletion”
I want to understand what a comment means, and I couldn't ask in a comment. In this question, someone asked why use an op-amp with a photodiode rather than just a resistor. The answers and comments ...
0
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2answers
110 views
How would I have destroyed these photodiodes?
I was trying to fix a light sensor module and using a diagnostics tool for it found that 1 of the 4 photodiode sensors was faulty (it was reading 0xFF.) As I don't knowwhich photodiode corresponds to ...
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0answers
40 views
Which InGaAs photodiode to use? How to connect it to ADC? Which ADC to use?
I want to create small and reliable device that could measure concentration of some substances in liquid using Beer–Lambert law. It will contain 4 LEDs (550, 650, 950 and 1550 nm ones), photodiode, ...
0
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0answers
18 views
Automotive Lidar optical testing
What is meant by Lidar optical testing? The optical section of Lidar contains
1)Laser diode
2)Tx/Rx optics
3)Photodiode
Whether it meant testing the above sections? If so,What parameters are tested in ...
1
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0answers
46 views
Photodiode and Phototransistor circuit
How can I design a circuit that characterizes photodiodes and phototransistors (as output/input)? That circuit should communicate electronically over an isolated link where one side runs a low voltage ...
0
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0answers
14 views
A light dependent current astable multivibrator
i have basic knowledge about multivibrators and how a photodiode is operated but i'm having trouble trying to combine them into one circuit. Suppose if i am to operate the photodiode on the circuit as ...
0
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2answers
51 views
Low precision flash detector
I'm interested in flash detection, what would be equivalent to 1000 FPS. High speed cameras that do this are too expensive and too heavy and provide too much information. In the long run I'm going to ...
3
votes
3answers
230 views
What is the response current of a photodiode to an LED emitting light at different intensities?
Let's say I have one of those conventional through-hole LEDs and I'm applying a sinusoidal voltage to it. From what I understand, at a given time, the same LED is either on or off, and to virtually ...
0
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1answer
66 views
Applying a forward bias to a photodiode to shift output
I am using this TIA circuit and photodiode in photovoltaic mode.
I'd like to modify the circuit such that at zero light a positive voltage is produced at Vout. And as more light falls on the ...
2
votes
4answers
136 views
Design of a simple transimpedance amplifier for large area photodiode
I'm a mechanical engineer, who has the luck to design an easy transimpedance amplifier circuit to convert the current of a photodiode to a voltage between 0 and 5V (without really knowing anything ...
1
vote
2answers
70 views
Would this photodiode sensor work better in series or parallel?
I am working on a photodiode small object sensor that detects and records signatures of objects passing through an array of photodiodes facing an array of IR LEDs. I am connecting the photodiodes to ...
3
votes
2answers
480 views
Photocurrent in photodiode smaller than expected
I have a question regarding the usage of the phototransistor SFH 203 P, which I want to use for a project, where I need a small fall- and rise-time. The data sheet (I think) implies that if I use the ...
0
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0answers
44 views
Conditional analog sample and hold (analog override?) - circuit suggestion request
Preamble: I have a LED driven by an opamp-based constant current source (CCS). It works fine, I can set up current required and it is reasonably stable. The problem is, that LED forward voltage drops ...
12
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2answers
5k views
Photodiode amplifier circuits - why use an op amp instead of just a resistor?
Beginner question here. I've built a photodiode light sensing circuit in class and internship such as this one:
I don't understand what it is doing over a simple circuit such as this one:
Can anyone ...
0
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2answers
84 views
Photodiode Equivalent Circuit
I have some problems on understanding this equivalent circuit for a photodiode (picture taken from this article):
The author states that:
The equivalent circuit for a photodiode is shown in Fig. 1, ...
0
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1answer
80 views
LM324N transimpedance amp for photodiode: Too low output, smaller feedback resistor gives greater output, not lower
I'm trying to build an optical power meter using a photodiode in photoconductive mode and a LM324N OpAmp:
simulate this circuit – Schematic created using CircuitLab
However, the output voltage ...
1
vote
0answers
71 views
Confirmation of connection between TSAL5300 IR sensor and BPW34 photodiode
I need to check whether my NIR LED sensor and BPW34 photodiode connection are correct or not. Does my IR sensor have to be infront of the photodiode?
I am going to place my finger on the IR sensor to ...
0
votes
1answer
53 views
Arduino - reading translated voltage gain from transimpedance amplifier
I implemented this circuit with a feedback resistance of 330 kilo ohms and a photodiode, which detects wavelengths in the infrared range.
I used the LM358 to amplify the photocurrent into voltage gain....
0
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1answer
80 views
Is it possible to model a PIN InGasAS photodiode in a SPICE simulator?
I want to know if it is possible to model a InGasAs panchromatic PIN photodiode, in accord with datasheet, in simulator SPICE MicroCAP 12. Because the supplier doesn't provide a SPICE model. And if it ...
0
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0answers
51 views
Simulation of photodiode in Micro-CAP 12 [duplicate]
I am beginner in simulation S.P.I.C.E. and I use the simulator Micro-CAP 12 to simulate an electric schematic.
I want to simulate the photodiode PIN InGaAs IG17-series and to monitor graphically the ...
0
votes
1answer
54 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 ...
0
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2answers
255 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 ...
0
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0answers
14 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} ...
0
votes
2answers
127 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 ...
2
votes
1answer
45 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 ...
3
votes
2answers
82 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 ...
0
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1answer
46 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 ...
0
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2answers
120 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 ...
0
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1answer
48 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 ...
1
vote
1answer
92 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 ...
0
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0answers
93 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-...
1
vote
4answers
561 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 ...
0
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3answers
199 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 ...
0
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1answer
38 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 ...
0
votes
3answers
94 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 ...
1
vote
1answer
129 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, ...
0
votes
3answers
90 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/...
0
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1answer
56 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 ...
0
votes
2answers
58 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 ...
0
votes
2answers
122 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 ...
0
votes
2answers
55 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 ...
1
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0answers
87 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 ...
0
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1answer
58 views
Photovoltaic cell creation
In order to create a photovoltaic cell all I need is a photodiode connected parallel to a capacitor right?
0
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1answer
152 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, ...
1
vote
1answer
254 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 ...
1
vote
1answer
77 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 ...
