Principle of PDM

[Yuya_O]

I read some articles of delta sigma modulation on the internet but I can’t understand the principle of it. Someone could you explain the principle ?

 

[crutschow]

Delta-sigma modulation generates a single-bit output, where it achieves higher conversion efficiency by transmitting only the changes (delta) in value between consecutive samples, rather than the actual samples themselves.
It achieves high resolution by greatly oversampling the signal (much higher than the minimum Nyquist frequency of twice the highest signal frequency), and then using a digital (decimating) filter to generate a conventional multi-bit, lower frequency digital output of the signal.

Have you read this tutorial?