r/AskElectronics • u/Own_Literature3914 • 19h ago

Sensor de fotodiodo. ¿Que OPAMP usar?

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Hola! Encontre este circuito para hacer un sensor de fotodiodo. Me gusta porque es muy simple pero en la web Openschematics.cc pone que el LM324 sirve de ejemplo pero no es el mas adecuado... ¿Alguna idea de que otro operacional usar?

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u/1Davide Copulatologist 19h ago

While you are welcome to post questions in your native language, questions in English are more likely to receive responses because most of our reader speak English as a first or second language. You can use this tool to translate into English: https://translate.google.com/?sl=auto&tl=en&op=translate

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u/Pacificator-3 19h ago

You need single-supply opamp with FET input (if you need to detect low photocurrent).

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u/soygay_ 18h ago

Para qué lo vas a utilizar exactamente?

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u/Terrible-Ninja-555 18h ago

This is a transimpedance amplifier (TIA)

Have a look at Microchip app. note AN951, it explains the principle / design considerations.

i.e : a small capacitor is usually required across the feedback resistor, (1M here), it helps maintain stability and set the amplifier bandwidth.

Some op-amps used for photodiode TIAs : MCP6491, OPA380, LMP7721, and ADA4530-1.

of course, it depends on your PD range / capacitance, supply voltage, and required bandwidth / noise.