LMH32404RHFEVM:Modification method for evaluation using APD

Hello,

   If you are able to connect via blue-wiring, then yes you can change the AC coupling capacitor and series resistor to 0Ohms. Both have to be removed, and shorted. Also, remove the capacitor to ground at input (C21, C25, etc). This was placed to emulate the PD input capacitance. And, you can remove R11 and C22.

   However, as original thread linked stated, this board was not designed to be reconfigured to receive a true current input via a photodiode pad configuration like the introduction paragraph highlighted. This was a document mistake and one we will have to fix. But, it can still receive a current input following above alterations, but would require blue wiring or a separate board with your photodiode biased then connection via sma.

   The board that has a photodiode connection that you can solder on to the back of the EVM is the LMH32401: https://www.ti.com/tool/LMH32401RGTEVM. This device is the single channel variation of the LMH32404.

Thank you,
Sima