I am using LT1037, I used Rf1=200K, Rf2=100 as feedback resistors which equals to 2000 gain, but what I am getting is only 600!!
could someone give me an explanation for this?
Gain of 2000 is about 66dB, which does not really seem to
challenge most decent op amps' AVOL.
But that much gain could easily rail the amplifier, only need
7.5mV input difference to make 15V at the output under
that gain setting. Might look to see whether the output
is clipping.
Assuming a maximum open-loop gain of 106 dB and a first pole at 10Hz a closed-loop gain of 66 dB is possible up to several hundreds Hz only. EDIT (because of the next post from FvM): The foregoing statement assumes a unity-gain compensated opamp.