So instead of PWM he decided to experiment with pulse density modulation. The idea is to use smaller pulses over a longer period of time and make the average power equal to the percentage motor ...

PDM — pulse density modulation — is similar to PWM and, like PWM, requires a filter that could range from a simple RC network to an active filter. You can see the result in the video below.

The AR36T05 is a soft macro low-power high-performance digital microphone interface modulator IP. The IP converts stereo/mono 1-bit pulse-density modulated (PDM) bit stream data from external ...