Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It only takes a minute to sign up.
Sign up to join this community
Regarding this question -> Transimpedance amplifier with a non-ground reference
What are the benefits of having an ideal absolute static reference voltage instead of just simple GND on the non-inverting input of a transimpedance amplifier using it with a photodiode?
Does it somehow eliminate the problem with dark current interference or are there any other benefits?
The voltage on the non-inverting input of the opamp can be used to provide a bias for the photodiode when there is no negative supply available.
The inverting input will be driven to the same voltage as the non-inverting through the feedback resistor.
Using photodiode in photo-conductive mode (reversely biased) improves dynamic response due to the lower junction capacitance. The bias can be achieved as you described. Additional benefit may be that you are adding an offset to your signal. Small positive offset is often beneficial in the case you are using unipolar ADC to convert the signal. If your op-amp (and other parts of the chain all the way to the ADC) have negative offset you wouldn't have a way to track small signals around zero. With a positive bias this would be possible and you may be able to subtract the measured offset at dark state of the photodiode.
