Method and system for analog to digital conversion using digital pulse width modulation (PWM)

摘要

A system and method for analog-to-digital conversion using digital pulse width modulation (PWM) is disclosed. The method and system according to the disclosed invention converts an analog input signal to a digital signal in pulse code modulated (PCM) form. The disclosed invention uses a feedback circuit to perform PWM of the analog input signal. The PWM signal is then decimated to obtain the digital signal in PCM form. The system according to the disclosed invention requires lower operating frequency and dissipates lesser power than prior art systems providing the same sampling frequency and resolution. The operation at a lower frequency is achieved by obtaining two samples from every pulse of the PWM signal; the first sample being obtained from the right duty ratio, and the second sample being obtained form the left duty ratio. Further, the disclosed invention has lesser implementation complexity and higher signal-to-noise ratio than prior art.