I have read through the datasheet and, I am not sure if the AD7731 should be disconnected from the analog signal when performing internal zero scale and internal full scale calibration.
For example, channels 5 and 6 in full differential mode, AIN- driven with a 2.5v voltage source (LM4140) and AIN+ driven from a custom sensor through an OpAmp. REF_in- is tied to ground and REF_IN+ is 5v
Should I disconnect the 2.5v and the sensor OpAmp from the device for calibration?
Should I disconnect only the sensor OpAmp?
Should I not disconnect anything for calibration?
Thanks for your input.