Patent ID: 7576604

Claim:
An all-digital class-D audio amplifier comprising: a pulse-width modulation (PWM) wave generator adapted to generate a PWM wave; an interpolator adapted to receive an input audio signal, up-sample said input audio signal; and down-sample said input audio signal to a PWM wave switching frequency; an audio speaker adapted to broadcast an amplified version of said input audio signal; a pair of metal-oxide-semiconductor field-effect transistors (MOSFETs) driven by said PWM wave and said input supply voltage, wherein said pair of MOSFETs transmit said amplified version of said input audio signal to said audio speaker; a natural-sampling and pre-distortion circuit adapted to (i) generate a pre-distorted natural-sampling frequency point for said PWM wave switching frequency, and (ii) account for digitized power supply ripples for an input supply voltage used to drive said audio speaker; and an analog-to-digital converter (ADC) adapted to digitize said power supply ripples or any power supply distortion.