My customer is seeing an issue related to ADC offset with the ADS5474.
They are driving the VRef with an external reference. When they tie the two inputs each with a 50 Ohm resistor to GND they see about <1mV of offset which is well within the specification. However when they tie them off to the VCM they get 20mV. Do you have any ideas why this is the case?
They are using a 2.5V reference at the Vref pin of the ADS5474. The VCM output is at approximately 3.15V.