Patent ID: 7809346

Claim:
A digital audio receiver, comprising: an AM tuner for demodulating an amplitude-modulated signal, at a selected AM tuned frequency, into a baseband audio signal; and a digital audio amplifier, coupled to the AM tuner, and comprising: an interpolation filter, for receiving an input datastream corresponding to the baseband audio signal at a first sampling frequency, and for oversampling the input datastream by a multiple; a sample rate converter, receiving the oversampled datastream and for producing a converted datastream at a converted sampling frequency; pulse-width-modulation (PWM) circuitry, for generating, at a PWM frame rate, pulse-width-modulated signals corresponding to the converted datastream; and clock circuitry for generating clock signals to the sample rate converter and to the pulse-width-modulation circuitry to select the converted sampling frequency responsive to the AM tuned frequency.