Using the PDM microphone on the AD2428WC1BZ board, we attempted to input a 1 kHz sine wave. However, the data captured on the A2B Bus Monitor shows a square-wave output instead of a sine wave.

Hi，

We are building an A2B network with an AD2433 configured as the main node and an AD2428WC1BZ configured as the sub node. Network discovery completes successfully, and the main is able to receive upstream audio data from the subnode. However, when a 1 kHz sine-wave signal is applied to the PDM microphone on the AD2428WC1BZ board, the waveform captured on the A2B bus appears as a square wave rather than the expected sine wave. We would like to understand whether this behavior is related to the PDM microphone configuration, slot mapping, decimation settings, or any other audio processing configuration in the AD2428WC1BZ.

The software I am using is SigmaStudio+ Rel 2.3.0 together with ADI A2B Software Rel 2.0.0. Could you please advise what the possible causes of this issue might be?

Thanks！