I'm building an adc and amplifier circuit for sensing a differential signal out of a pressure sensor. My plan is to use a circuit very similar to what is seen below:
The total differential output from the pressure sensor will likely be quite small (less than 1mV) so the amplifier will have 30x or 100x gain so I am worried about noise on the output. The frequencies I want to measure are very low (1-30Hz) so I can put in an appropriately designed RC circuit. However, since noise is an issue, I was considering using a Sallen-Key low pass filter on each of the outputs from the amplifier so I can get a sharper drop off.
Does it make any sense to do this? I'm worried that voltage offset errors from the sallen-key amplifiers would change the results of the ADC conversion of the differential signal.