There are three analog input configuration examples on the AIC3254 CS Tool. The first one "High Performance Stereo Recording", the second one is "Low Power Stereo Recording" and the third one is "On-Board Differential Microphone".
My question is why only the "On-Board Differential Microphone" example doesn't need to set the "common mode"? We don't understand what "common mode" is, and we don't know whether we need to set it?(Our analog input is using a differential microphone)