Abstract: A differential amplitude pulse width modulation (aPWM) digital to analog converter (DAC) is provided, including an aPWM module for generating differential pulse from an input digital audio data stream, a power driver module for providing energy to a terminal load and a filter for removing unwanted harmonic signal to reconstruct analog signal, wherein the aPWM module further includes a PWM pulse generator to convert the digital input numerical code to a series of time domain pulse width; an amplitude modulation unit, for increasing time domain resolution of the pulse width, and a differential pulse width generator to convert series of PWM pulse into voltage and time domain differential form; the power driver module further comprising a pulse amplitude selector, connected to a power source, and two power stages connected respectively to the pulse amplitude selector.