AnsweredAssumed Answered

ADAU1361 Noise When Unplugged

Question asked by Galenthas on May 21, 2018
Latest reply on Jun 1, 2018 by DaveThib



Hope all is well.


We use ADAU1361 in our design with two single ended microphones. 

The two mics are connected to negative inputs as pseudo differential and grounded with AUDIO_GND.

When we unplug each microphone, we observe high background noise (not your typical noise floor). 


We have the EVAL-ADAU1361, we do not observe the same using the same settings.

Below is the schematic;



We experimented with capacitor and resistor values but we were not able to find the cause of this floating noise.

Any help is much appreciated.