I'm trying to use OPA625 in a current meter design. At first stage, the input signal is passed through a voltage follower to lower the output impedance. Here is a circuit:
According to the datasheet, the input offset of OPA625 is about 15±100 uV. With gain = 1 it translates to a similar output offset. However, this is a simulation result:
The output voltage doesn't seem to drop below 9 mV. OPA625 PSpice model is used (downloaded from WEBENCH® Design Center). I'm now quite sure why is there such a big offset in this circuit, are there any other factors contributing to it?