I am using the on-board differential amplifier on the AD7763 to provide the appropriate offset to my input signal before going to the analog to digital converter. Normally, this all works correctly. However, I have a few boards that are not providing the proper DC offset. Can anyone provide a reason why this would not be working? Here are my operating parameters:
Differential input signal scaled to +/ 1.024V based around ground before going to the on-board diff amp.
See schematic below