The AD7682 datasheet describes that there is a pin called COM which can connect to 0V or VREF/2V. But in which case we should connect the COM pin to the 0V and in which case connect to VREF/2V? What's the main function of the COM pin?
The AD7682 has REF pin and REFIN pin. The datasheet describes that if connect the REFIN to the reference voltage. The REF pin will produce a buffered reference voltage that comes from the REF pin. Would the ADC working if i connect the REFIN pin to the reference voltage and hang up the REF pin?