Bias resistor in TIA configuration

[nihial]

Hi,


I sometime see a resistor in series with the photodiode in TIA configuration.

However I don't understand its purpose and I didn't really find an explanation.

Anyone fort a short answer and a link to a long answer?

Best regards

[BillyO]

I've never seen this myself.  Do you have a link to an example?

The only thing I can think of is current limiting.

[nihial]

For example in https://www.analog.com/en/resources/technical-articles/how-to-effectively-design-and-optimize-tia-interfaces-of-lidar-systems.html

I don't talk about the resistor with the capacitor for ac coupling but the one even present in DC coupling configuration

[Gyro]

That one is for current limiting, note the '-HV', avalanche detector diodes work at much higher voltage than the opamp supply rails.