miniDSP Ltd, Hong Kong /
www.minidsp.com
/ Features and specifications subject to change without prior notice
16
4.2
PDM
OVERVIEW
PDM stands for Pulse Density Modulation. It is an ideally suited digital audio transmission method for MEMS
microphone as it brings benefits of digital audio (noise immunity, high quality audio) at very low cost.
PDM CLK
The PDM clock always runs at 3.072MHz.
PDM[0..7]
Each data lines carrying a stereo feed of 2 x microphones by using the SELECT PIN. The timing of
data lines is as illustrated in the following diagram:
The UMA-16 uses one stereo PDM data line for two mics with a standard configuration as per Knowles app note.
All lines use a 3.3V logic level. Ensure that connected circuits use a compatible logic level.
