Other Parts Discussed in Thread: ADS1261
This is an application for a scientific instrument. I have two signals of interest, a sample signal (S) and a reference signal (R) measured simultaneously on the same instrument. My desired output is S/R. Aside from noise, S and R are both positive and R>=S, so my output scales from 0 to 1. Rather than measure the two signals separately, I would like to measure only S while using R as an external reference voltage for the ADS1262. Will this work, and if so, do I need any special signal conditioning?
My device will attach to sensors with a standard output of 2V. I plan to set FSR to 2.5 and would like to bias the voltage using AINCOM = 0.25V to allow room for noise below 0V and above 2V. Can I do this rather than setting AINCOM to midrange?
Because S and R are often identical, using the PGA will usually put the output voltage above FSR. However there may be portions of the signal where S/R is small and use of the PGA would be useful in reducing noise, Worst case would be PGA =32, resulting in a 64V input for S/R = 1.0. Could this damage the ADS1262?
Thanks for your help.