A class D amplifier is provided. The class D amplifier includes an
interpolator, a sampling rate converter, a pulse width modulator, a
sigma-delta modulator, and a pulse width modulation (PWM) pulse generator
(PPG). The sampling rate converter interpolates the output of the
interpolator such that the sampling rate converter up-samples the
interpolator output by a factor that is greater than one and less than
two. The pulse width modulator outputs a multi-bit digital signal. The
sigma-delta modulator performs sigma-delta modulation on the pulse width
modulator output, the order of the sigma-delta modulation is
programmable, and the output of the sigma-delta modulator is a multi-bit,
digital signal. At least one of the orders to which the sigma-delta
modulator can be programmed is greater than two. The PPG provides a pulse
signal such that the width of each pulse is based on the value of the
sigma-delta modulator output.