Transimpedance Amplifier

Other Hardware General Electronics
1

Hi,
What's the rule of attached image capacitor and variable resistor in a photodiode transimpedance amplifier?
Thanks

op amp.png

2

What are C1 and R2 supposed to do?

Useful reference on photodiode amplifiers.

3

jremington:
What are C1 and R2 supposed to do?

Useful reference on photodiode amplifiers.

Thanks a lot. It's a valuable information. But I couldn't find my answer!

4

But I couldn't find my answer!

The question made no sense, and neither did the schematic. C1 and R2 have no obvious function.

5

The photodiode tries to create a negative voltage (current).
The opamp tries to counteract that (make -input the same as grounded +input) by adding a positive current through R1.
How much the opamp has to slam on the brakes can be measured as a voltage on it's output.
The cap is explained on page 24 of the linked document in post#1.
Leo..

6

Wawa:
The photodiode tries to create a negative voltage (current).
The opamp tries to counteract that (make -input the same as grounded +input) by adding a positive current through R1.
How much the opamp has to slam on the brakes can be measured as a voltage on it's output.
The cap is explained on page 24 of the linked document in post#1.
Leo..

Thanks guys