rockpool.devices.xylo.syns65302.afe.pdm.pdm_adc

This module contains the PDM-based ADC for sampling the input audion signal. It consists of two main parts:

  1. a deltasigma based PDM microphone that converts the input analog audio into a PDM bit stream where the relative frequency of 1-vs-0 depends on the amplitude of the signal

  2. a low-pass filter follows by decimation stage that processes the PDM bit stream and recovers the sampled audio upto a given bit precision.

In brief, PDM microphone with its internal deltasigma modulation followed by low-pass filtering + decimation module implemented here yield an ADC for the input analog audio signal.

The low-pass filtering is implemented as a polyphase filter structure to consume as less power as possible.

Classes

PDMADC(*args, **kwargs)

Pulse-density modulatio Analog-to-Digital (ADC) module for XyloAudio 3 chip consisting of