I am developing a system that makes use of the ADMP421 MEMS microphone and the ADAU1761 audio codec. I have been troubleshooting a problem where there is a large bias to the audio signal and I was informed on the MEMS microphone discussion thread that the ADCs high pass filter should be enabled (0x4019 bit 5). Although this works, it takes a half hour for the bias to drop to a third of its original value and it never reaches zero. Is there a register setting that I am missing that would speed up and improve the performance of the ADCs high pass filter or should I use a filter block in the dsp schematic in Sigma Studio?
