I also have the issue with the ADA4254, which seems to be frustrating several people:
I'm using the ADA4254 as a preamplifier on a measurement card for an AD4134. AVDD is set to 5V, VDDH to +12V, VSSH to -12V, and VCOM is sourced from the AD4134 at 5V/2. +/-IN1 is intended to measure the DC branch, while +/-IN2 is meant for the AC branch.
No matter how I configure it, the PGA always amplifies the input IN1 by a factor of 2. I can cleanly measure a voltage of +/-1V at the output as +/-2V. When I read the registers back, I can see the values I wrote into them, but its behavior doesn't change. I can't configure either the gain or the input. The GPIO functions (all set as outputs in my application) work flawlessly, indicating that communication seems to be working fine.
What can I do to get to the bottom of this issue?
Thanks and regards, Martin.
Thread moved from Instrumentation Amplifiers to Amplifiers
[edited by: emka at 11:28 AM (GMT -4) on 25 Oct 2023]