I want to use the ADUCM361. Analog input signal is single ended and is between 200mV and 500mV (referenced to AGND). PGA gain shall be 2, as I need the input buffer. Data format is unipolar and the internal 1.2V reference shall be used. My question: As I need the input buffer, the positive input buffer must be turned on, of course. But what do I with the negative input buffer? Turn-on or turn-off?