Hi everyone,
I have 3.3 V analog as well as digital voltage and 0V as AVSS. I am using unipolar power supply to power ADS 1298 . Please tell me how much voltage should i apply in vrefp pin with circuit and component to connect. I had refer to datasheet and it explain 2.5 V but i saw a schematics online (attached) which has +2.5v and -2.5V as AVSS but the datasheet explain that VREFP must be AVSS+2.5. But in the schematic i had found, whose AVSS is -2.5v and AVDD is +2.5 v which clearly violet the datasheet rules. So i am confused and need a solution.

 

AVSS = -2.5V and AVDD = +2.5V do not violate 7.1 Absolute Maximum Ratings of VREFP input to AVSS AVSS – 0.3 AVDD + 0.3 V. For your 2.5V and -2.5V rails that is 5.6 volts differential. Referring to 7.3 Recommended Operating Conditions we see 4 V differential. Double check what I post as I have been known to make mistakes.

Datasheet
https://www.ti.com/lit/ds/symlink/a...=https%3A%2F%2Fwww.ti.com%2Fproduct%2FADS1298