I would like you to confirm about below.
* There are two analog power (AVDD and REF) in ADS8881.
According to datasheet of ADS8881(Figure 45. Detailed Block Diagram), it seems that "REF" voltage is used for all of analog power source (supply for ADC, clamp voltage of input line).
According to datasheet, "The internal circuits of the device operate on AVDD" is described. So, this voltage is used for something. However, I'm not sure which purpose this supply is used.
So, could you please tell us internal usecase of this voltage ?
(Especailly, I would like to know when AVDD become low voltage than min spec of datasheet, which function will be affected.
One of function, I guess that this voltage is used for POR(Power on reset). so I can see that device will not boot up as one of issue..)