I want to create a single-sided input amplifier with very high input impedance (it is fed off a 10M divider), precise gain, low noise and low drift. Bandwidth up to 1MHz would be nice, but 100's of KHz will do. I started off looking at the CA3160, but got onto looking at instrumentation amps, since this is for a voltmeter which should be able to resolve 3mV.
Comparing data sheets, for my purposes there doesn't seem to be much to choose between the op-amp and any of the in-amps I can afford.
So I was wondering, with the inverting input grounded in both cases, is there any advantage in using an in-amp, or had I better stick with using an op-amp, and if this is the case, is there anything more suitable than the CA3160?
TIA