Dear Sir / madam,
I want to design a high speed low noise amplifier for measuring very low current (nano-amp range). I want to amplify it 1000 times (to get output in micro-amp range). I came to know about opa 659 IC with very low input bias current (10pA) and quite high slew rate 2550 V/ns, but i want to know about the noise performance of this IC. Is it possible to design a 3-stage amplifier having gain of 10 at each stage with very low noise?
Earlier, I used opa847 with input noise of 0.8 nV / rt Hz and i got significant noise while using it on pcb board. Now since opa 659 has got 8 nV / rt Hz input noise, will it be fine to replace opa 847 with it? Can you please suggest me which IC will be better for this application?