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.
It is alright not to disconnect anything during calibration as long as the signals connected to the analog input pins of the device are within the specified limits and noise/interference free.