hi,
Just to confirm, looking at your last diagram.
You state that for the input to the OPA that the ZERO state is V=5.77477 on BOTH input pins and that the FULL SCALE differential input is V=5.7405 and V=5.67196
This suggests that the differential input signal is unipolar in sense and not bipolar, is this correct.?
If yes, then by using a standard 3 * opa IA, the output from the IA would always be unipolar in sense and the CMV cancelled.???
I see that you are using a differential input 24bit ADC with a SIGN bit to indicate input signal polarity.
As described above the ADC digitised output, assuming Vref for the ADC is 0.5*Vcc, would always be above the centre bit pattern, say positive.
Is this correct sofar.?