Re: Low drift OP amp for photodiode circuit

Phil Hobbs wrote:

There are lots of nice things about this method. One is that it's much
much quieter at very high gains--unlike 500G ohm resistors, capacitors
don't have thermal noise.

A 500G resistor has about 0.18fA/rtHz noise, that's about as much noise as a
0.1pA (leakage) current has intrinsically. So if your opamp is (and needs to
be) better than that, use the integrator method.

How does the LED reset method work? Using the LED as a photoswitch?

I also like the supply reversal method conceptually but have never used it.

robert
.

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