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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!

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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.

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  • \$\begingroup\$ So, does flowing "away" from the inverting input mean to ground? \$\endgroup\$ – Zack Frost Jul 3 '14 at 17:20
  • \$\begingroup\$ No it could mean flowing away to minus infinity via an infinite impedance (or anywhere in between this and 0V) - a TIA requires the input to be current because the inverting input is kept at the same potential as the non-inverting input due to action of negative feedback thru the feedback resistor. \$\endgroup\$ – Andy aka Jul 3 '14 at 17:39

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