OPA857: Why there is no amplify input signal?

Hi Paul,

the OPA857 is a TIA. A TIA has a current input, not a voltage input. A photodiode or similar is expected to be mounted to the input pin of OPA857. Please see figures 39 and 44 of datasheet.

Kai

Kai,

The figures you mentioned are below picture?

And customer mentioned they are reference TIA-00663 circuit design and didn't follow figure39 topology.

So is there any way can directly check OPA857 work or not?

Thanks

Hi Paul,

pin 13 must be connected to GND for normal operation, not VDD:

Kai

Hello Paul,

  The TIDA-00663 reference design uses a photodiode before the TIA which is shown in this block diagram:

Thank you,

Sima