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Questions tagged [photodiode]

A photodiode converts light to an electric current.

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1answer
47 views

How to connect a 2 pin photodiode?

Initially, I have used 3 pin photodiodes, where the anode is connected to the resistor and has a wire which goes to group and the other goes to an analogue input to read the voltage. The cathode is ...
0
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2answers
51 views

Correct use of op-amp to amplify photodiode in reverse bias

So I have a photodiode in reverse bias, from which I intend to measure my pulse. Currently, my schematic looks as follows: simulate this circuit – Schematic created using CircuitLab Weirdly,...
3
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4answers
761 views

How to tell how sensitive a photodiode is?

I am looking to buy some new photodiodes for a project. Currently, I have been using expensive photodiodes with a picosecond level rise and fall time and a very small area to pick up light. The ...
2
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4answers
496 views

Photodiode almost no mV at analog port

So I have bought a photodiode, which I intend to hook up to the analog port of my Arduino, so that I can measure differences in the light that the photodiode picks up. I realized, that when I don't ...
0
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0answers
47 views

Circuit wont work with dc motor

This circuit wont work with the DC motor included but works fine with out it, what can I do to make it work? I need the motor to work when it receives the infrared signal, thanks.
0
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1answer
45 views

High speed photodiode for laser pulse width measurement

I want to measure the temporal width of a Q-Switched laser (which should be close to 5 ns) and the delay between two lasers that I send in my experiment. The delay is between 1 ns and 1 µs. Wavelength ...
0
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1answer
26 views

where do i find max short circuit current of photodiode?

I'm trying to convert the current signal from a photodiode to voltage through a transimpedence amplifier. The photodiode is put in photovoltaic mode in order to get the greatest accuracy and lowest ...
0
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1answer
29 views

Schematics of PIN Photodiode interfacing with an ADC

This question is in continuation of my previous question. I am moving forward with PCB designing now. I have selected low input-bias current op-amp AD8616 for converting current signal into voltage. ...
0
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1answer
95 views

Laser Microphone setup

I am currently constructing a laser microphone using 5mW red laser pointer source based on the idea below, not directly output to a speakers or headphones, but the signals must be fed into computer ...
0
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1answer
28 views

The breakdown voltage of APDs

what does the breakdown voltage of an APD tell me? I know certain methods how to determine it but, what happens after reaching that point? More specific: Is the gain afterwards constant or still ...
0
votes
1answer
78 views

Why is this photodiode operated in reverse bias

Referring to the following document by NXP on figure 9. The cathode of a given photodiode is connected to the transimpedance amplifier in forward bias. To me, this seems wrong, as almost every ...
0
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2answers
58 views

Better resolution with photodiode (LTR-536AD)

I want to build something like a fog-sensor. I'm using a laser and on the other end (~20m) I have a LTR-536AD photodiode. I hooked the photodiode to an arduino and was monitoring the voltage. My ...
0
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1answer
77 views

Correct use of transimpedance amp

So I realized that it might become a necessity for me to use a transimpedance amplifier for a pulse watch that I intend to make. Some background: The pulse watch shoots light at 940 and 660nm at ...
0
votes
1answer
53 views

Does this photodiode need an operational amplifier?

I'm trying to make a circuit for a pulse watch, which should be capable of measuring blood SpO2. I use 2 LEDs for each wavelength (respectively 660nm and 940nm) to shine at the upper wrist. The ...
0
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1answer
44 views

Photodiode temperature compensation

The goal is to design a circuit that can accurately measure light intensity with little temperature dependency. Common application uses photodiodes to do so. Photodiodes can be measured either in ...
1
vote
1answer
114 views

Arduino breakout schematic for FDS100 Photodiode

This is the first time I'm drawing a schematic, thus why this question seeks to get clarification from you experienced engineers :-) A little background information: I'm trying to draw a circuit ...
1
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0answers
47 views

About measurement of pulse using oscilloscope [duplicate]

When I measured the optical pulse using photo-detector and oscilloscope, some negative voltage was measured after strong peak. What did I get negative voltage? How is it possible?
1
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0answers
40 views

Electronics interface circuit for PIN Photodiode

I am designing an interfacing circuit for PIN photodiode which will be used in NIR spectrophotometer project. The PIN diode is <...
1
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2answers
35 views

Photodiode in photoconductive vs photovolatic configuration

I want to use a photodiode to measure light intensity, but I am not sure if the photodiode should be used in photoconductive or photovoltaic mode. From my understanding the photovoltaic ...
0
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0answers
23 views

Appropriate PCB Stack Up for Transimpedance Circuit

I'm designing a circuit involving multiple silicon photomultipliers that involves the necessity of multiple layers for my circuit. My circuit is shown below: simulate this circuit – Schematic ...
1
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2answers
59 views

Photodiode connection to ADC

I am designing a product where an ambient light sensor is used to adjust the LCD's brightness. The following circuit is implemented to read the light sensor. The ...
1
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0answers
32 views

Generate ultrashort rise times with photoconductive switch or photodiode

I am trying to produce voltage pulses with very short rise time (<15 ps), medium width (20 ns) and amplitudes up to 15 V. As a promising candidate I selected photoconductive switches and ultrafast ...
2
votes
1answer
34 views

PIN diode in RF switching vs. PIN diode used as photodiode

From what I understand, there are traditional photodiode components that are designed with PIN diodes, in which the gate is activated by light saturation. For a PIN diode component made for RF ...
-1
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3answers
107 views

Are IR emitter frequencies adjustable? Can modulation of the emitter variate material absorption properties?

A common LED emitter, Gallium Arsenide, apparently has a wavelength of about 760 nm. Then on the receiving end, there is a filtering circuit to eliminate ambient IR and to demodulate the message. Can ...
2
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3answers
82 views

Photodiode gate circuit noise

I'm building a chronometer for high speed projectile speed measurement. Currently i'm in the process of designing the projectile detection gate. It needs to be able to detect obstructions in light for ...
0
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0answers
50 views

Charge accumulation in photodiode amplification circuit

I'm using an op amp to read a photodiode as pictured here: This is used to detect a 5mw laser diode from a few feet away. The problem is that the circuit appears to accumulate the charge (not sure ...
1
vote
1answer
66 views

visible light communication data reception

My project is on visible light communication. I use a 555 timer circuit to modulate data with 200 KHz signal using a 3 watt LED. At the receiver I use a photodiode (PS100-6-CER2PIN First Sensor ...
3
votes
5answers
980 views

Infrared LED and Photodiodes

I am currently working on a project that uses an IR LED and a photodiode in a proximity sensor configuration (shown below). My question is, I have read some sites that state that your human body ...
1
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1answer
37 views

Can a photodiode tolerate a reverse bias beyond its specification

While searching a literature related to my experiment I come across this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4424026/pdf/PP_PP201500119.pdf . On the page 27 under the section SRS ...
2
votes
2answers
144 views

High-speed Infrared UART link with photodiode

I need short-distance (about few centimeters) wireless IR UART link with 250k+ baud. I tried to use phototransistor (assume Q1 is phototransistor). Q3 is used to prevent inverting signal. simulate ...
1
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2answers
75 views

Noisy amplification and low light: photodiode and op-amps question

My formal education was in mechanical engineering and I’m well trained in some CS as well. Yet here I am on an electrical project (that will eventually turn CS). I have been lost and confused for many ...
0
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0answers
86 views

Advantages and disadvantages of voltage output vs. current output PMT modules

Context: I am building a custom right-angle static light scattering setup to measure aggregation of biomolecules in aqueous solution. I need the instrument to be as sensitive as possible, to allow ...
0
votes
1answer
56 views

Filtering current spikes in photodiode transistor selector

I am building a circuit for sensing photocurrent from a photodiode. The diodes are manufactured with selection transistors to form an active matrix and below is a model of a single pixel consisting of ...
2
votes
3answers
57 views

Photodiode selection for fluorescent probe [closed]

At the moment I am trying to build a DIY fluorescence detector using the Amplex Ultra Red probe with excitation and emmission maxima at 568 and 581nm respectively. I just have problems choosing the ...
0
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1answer
31 views

Photodiode Trans impedance amplifier design

Am designing a trans impedance amplifier for photodiode from first sensor PS-100E.Am using LM 358 op-amp.To calculate the feedback resistance ,I should know the short circuit current of the photodiode....
0
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1answer
85 views

Amplifying current from a photodiode

i'm coming back from my previous post, to give some futher details: here's my problem: We're going to supply power to a 4-motors drone with one/several photodiods. Here are the characteristics: 4-...
1
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0answers
23 views

Analyzing pinout of photodiode in a ic

I have dissasembled a pick up head from a CD Rom. I can control the laser and but I also want to "read" the photodiode that senses the light reflected back. It is packaged in a clear plastic and has 8 ...
0
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1answer
132 views

Transimpedance amplifier PCB layout

I'm trying to replace an avalanche photodiode board + external voltage amplifier combination that suffers from RF pickup due to cabling between the diode and the amplifier as well as low bandwidth due ...
0
votes
1answer
69 views

Photodiode scintillation detector for gamma spectroscopy

I'm trying to build a basic detector for x-ray or low energy gamma spectroscopy. I have a big photodiode with a CsI(Tl) scintillation crystal glued on top (Hamamatsu S8559 for x-ray detection [1]) and ...
1
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2answers
91 views

Working with RF Amplifiers for the first time

I'm designing a circuit to use an IF amplifier, specifically the ADL5536, to amplify the signal of an SiPM array consisting of the MicroFJ-60035 TSV SiPM by SensL. My goal is to use this amplifier to ...
3
votes
2answers
74 views

What is this? Identifying Proximity Sensor Chip (IR)

I am in a bit of a pickle. If anyone could help/has any ideas I will be very grateful - am aware this post is pretty long but thought if anyone was clever enough to know it would be you guys. If ...
0
votes
1answer
90 views

Photodiode + OpAmp + Arduino: Further Amplification

In order to measure the concentration of a methylene blue dye in water, I am using a 660nm high power LED and a photo diode with op amp setup as described here (schematic below): https://...
0
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0answers
122 views

Photodiode Amplifier Circuit Design

I'm working with a mid-infrared (~4um) photodiode model Lms43PD-03-CG (Datasheet) and a matching LED (Datasheet). (I can't switch from this photodiode/LED pair) I'm trying to make a functioning ...
1
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2answers
228 views

Equivalent circuit of a photodiode

What can I learn from an equivalent circuit model of photodiode like the following? I've actually gone the whole way beginning from doping semiconductors through each noise term to the amplification ...
0
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1answer
75 views

Photodiode amplifier gain question

I'm currently designing a circuit to convert an infrared signal (e.g. from an IR transmitter or a TV etc. remote control) and turning it into an audio signal. The first stage of the preamplifier is ...
1
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1answer
72 views

Diode modeling in verilog a

I am modeling a diode using verilog ams but I have a problem when I simulate its behaviour in different temperatures. The simple equation of the diode (Id=IS∗(eVd/Vt−1)) is not enough because it ...
1
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2answers
234 views

Bootstrapped Transimpedance Amplifier (TIA) - High Frequency Instability

I have constructed transimpedance amplifier in the hopes to achieve both high-gain (5kΩ) and high-bandwidth (50MHz) performance using the FGA21 photodiode, the OPA657 Op-Amp and the 2N2369 Transistor. ...
0
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2answers
116 views

How do I amplify the output current from a photodiode? (In photovoltaic mode)

I explain my self: we're going to make a photovoltaic cell with severals photodiods in series. Problem: the current isn't really high (I'm in photovoltaic mode, so no external biais source). I've ...
0
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2answers
57 views

covering sides of LEDS without adding heat

I'm doing a project in which a 5mm LED is near a 5mm phototransistor. There are times in which the sensor must pick up external light even with the LED on. I understand one option is to turn the LEDs ...
1
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1answer
60 views

Powering a power supply question

I purchased an amp for photodiodes from Amazon. It came with a 5v power supply. I am powering it with a 9v battery Everything seems to be working okay, but when I measure the voltage leaving the ...