Part Number: ADS1247 I am using the ADS1247 ADC with the AD8476 differential amplifier as the source to the ADC input. I am supplying each with 3.3V, but they are independent (both supply and circuit ground). I am using a 2.048V reference for VREF and the PGA gain is set to 1. I am using the mid-supply voltage (1.65 V) for the common-mode voltage on the AD8476. When I input a single-ended DC voltage (0.2 - 2.0 V) into the AD8476, I get the same respective voltage on the differential output as expected. However, when I connect the differential output to the differential input of the ADS1247 ADC, the differential output voltage changes (varies by +/- 0.01 mV - 0.1 mV). What could cause this? Note: I can shift where the voltages match from input to output by applying a fixed voltage to VOCM to shift it lower.
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