My question is: If I wanted a super precise, low noise, low TC drift, positive supply line could I just power the +A5V line from a voltage reference IC like the LTC6655LN-5? My circuit only needs about 3mA ( 6mA projected worse?)to run.
I have added the schematic to show that the +2.5V line is produced from the +A5V line. So therefore changes in supply to the ADC will also affect the +2.5V common mode voltage ( going to the CH- channel on the ADC), allowing for more linearity. So I am looking for a very low noise +5V source, with preferably low TC drift. I am unsure of the tradeoffs of using a voltage reference as the supply or using an LDO or using a reference+LDO combo (like the LTC6655LN-5 and LT3045) Like this: