Problems about TIA single input

[coxstreet]

Hi guys, I made a mistake that designed a TIA For differential input current signal from PD (see the attachment 1.)

But obviously, only one current signal from PD exits for A TIA input (see the attachment 2). So my question how to converge the single input signal to differential input based on my first design-that is differential input.

One common way is to set the one inputs current signal and the other sets the input common mode voltage. But how to implement it? How about other methods? Thank you!

cox

 

[erikl]

At the other input you could inject a current to compensate the dark current of the photo diode - or the DC part of the photo current, if this were constant, and such compensation useful for your application.