96 kHz.org
Advanced Audio Recording

Pulse Density Modulation

The method of PDM is a common technique to generate a one bit serial data stream from a parallel digital vector, to represent it's analog corresponding value at only one pin. This is often required to transport digital data or turn it into an analog value without a DAC. In fact PDM is a kind of DAC as explained here: PDM for Audio

 

Delta Sigma Conversion

 As explained in the article, delta sigma conversion generates an ideal one bit output of the digital value which in theory one has to be filtered appropriately to obtain an analog voltage. In the digital domain using FIR-filters this works fine because ideal mathematical algorithms are used.

Practically there are some problems:

 

PLD als Stereogegentaktendstufe - Jürgen Schuhmacher

 

Learn more about the function of this circuit in the former article mono amplifier.

 

Related Information

push pull audio out with one pin

 

 

 

 

© 2004 Jürgen Schuhmacher