Hello,
I want to apply a differential amplifier to a passive infrared sensor (PIR). The mean of the PIR output is about 0.7V and signal frequency I want to detect is around 1 - 10 Hz. Is it practical to find an opamp where I can get a gain on the order of 10^4 and input current on the order of 1uA / channel? If you can't recommend a specific opamp, what characteristics should I look for? I thought that I should look for a gain bandwidth product (GBP) / 10 Hz > 10^4, but the opamps in the electronics catalogs I've seen often times don't list the GBP and it's not searchable.
Thanks in advance.