Feedback Resistance: How Much to Use?

[cks]

http://sales.hamamatsu.com/assets/applications/SSD/si_pd_circuit_examples.pdf

The picture 5.

Usually, how much the feedback resistance to use? 100u ohms??

or,

how do we know how much resistance to use?

thank you.

 

[cks]

I think I find the answer, it depends on how much gain I want then I use how much resistance for the feedback resistance.

The answer can be found from here.

 

[berkeman]

Yes, the gain of the current-to-voltage stage depends on the resistance. It's definitely not 100 microOhms, though. That's probably a typo in your first post.

 

[cks]

From the picture, the resistor is 10k ohm, so if I want to have a gain of 10, the feedback resistor has to be 100k.

I know already. thanks for your reply.