A digital model of pulse-density modulation can be obtained from a digital model of the delta-sigma modulator.

Pulse-density modulation, or PDM, is a form of modulation used to represent an analog signal with digital data.

Pulse-density modulation (PDM)

In a pulse-density modulation bitstream a 1 corresponds to a pulse of positive polarity (+A) and a 0 corresponds to a pulse of negative polarity (-A).

LPCM is the method of encoding generally used for uncompressed audio, although there are other methods such as pulse-density modulation (used also on Super Audio CD).

In pulse-density modulation, a high density of 1s occurs at the peaks of the sine wave, while a low density of 1s occurs at the troughs of the sine wave.