Electronic – Single-Supply Transimpedance amp


So, I'm curious if there is a way to make a single-supply transimpedance amplifier op-amp circuit that uses a single supply. One thing that is important to me here is that it does not use a dc offset. This is because, if I were to ever use the circuit, it would be amplifying a steady dc signal! Just to clarify, I have no specific purpose for this at the moment. But I have certainly had one in the past!

Best Answer

If the input current signal (this feeds the inverting input) is always negative i.e. current flows away from inverting input, then the op-amp's output will always be positive with respect to the inverting input and this means a true ground referenced TIA. This sort of configuration sounds a trifle limiting but if the input is a photodiode then it works perfectly well provided: -

  1. The photodiode is connected the correct way round
  2. You allow for the op-amp's output not being able to swing perfectly down to exactly 0V

For #2 a rail-to-rail op-amp is a must but even these can be helped with a small negative supply (circa -100 mV) just to make the output linear down to true 0V/ground.