i was wondering if it is possible to use the input of the AD1938 with an asymmetric input and - for cost condition- with very few input component. The idea is to use only ADC-IN-Pos of the codec and load ADC-IN-Neg to ground. Of course, I've got 1/2 of the input range in that case but it's not the problem.
I try it and it's working but i've got a voltage drop on the input of the ADC i cannot explain. in this case R2=R3. Without ADC-IN-P, the divider bridge works fine. with ADC-IN-P, i've got only 80% of the expected value on R2. Am I doing completely wrong ?
thanks for your advice.