For homework I have to design a circuit which will take as input ultra violet light , it will convert it to an electric signal and then it will amplify it .Here is what I have done so far:


simulate this circuit – Schematic created using CircuitLab

Do I need to connect R1 to ground or not? Note that the VEE pin of the opamp is connected to ground.

This is what I think happens: When light is absorbed by the photodiode a voltage is created between the non inverting and the inverting pin.

In most of the projects I have seen the voltages in the inverting and in the non inverting pin of the opamp close loop with the ground and this doesn't close loop with the ground that is why I am asking if I need to connect it to R1 to GND.

  • 1
    \$\begingroup\$ Are you sure about ultraviolet? The photodiodes are usually used to receive infrared. Have you simulated that or done any research about receiving infrared with opamp, or directly asking if it will work? \$\endgroup\$
    – Justme
    Oct 9, 2020 at 15:50
  • \$\begingroup\$ Are you wanting to detect just whether there is light, or do you want to detect how much light there is? \$\endgroup\$
    – Hearth
    Oct 9, 2020 at 15:50
  • \$\begingroup\$ Just a thought, but if you edit your question to explain how you think this will work it will clarify your thinking and show us where you might be making any errors. \$\endgroup\$
    – Transistor
    Oct 9, 2020 at 15:53
  • \$\begingroup\$ Looks somewhat like a transimpedance amplifier meant for amplifying photocurrents. But there are errors. Do some more research on photodiode opamp circuits. \$\endgroup\$
    – glen_geek
    Oct 9, 2020 at 16:03
  • \$\begingroup\$ @Justme Silicon photodiodes are available from about 200-1000nm, so it is reasonable to use one to detect UV light, although you might need GaP photodiode for < 200nm. \$\endgroup\$ Oct 9, 2020 at 16:21


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