A Class-D amplifier system may include an input stage that includes an
N.sup.th order filter, where N>1. The input stage filters an input
signal to provide a filtered output signal, an input of the input stage
being configured to receive the input signal as a digital
pulse-width-modulated (PWM) signal. A comparator provides a quantized
output signal based on the filtered output signal. An output stage is
connected between a first voltage rail and a second voltage rail. The
output stage provides a switching output signal at an output that varies
between the first voltage rail and the second voltage rail based on the
quantized output signal. A feedback path connects the output of the
output stage with the input of the input stage, such that the N.sup.th
order filter compensates for variations in at least one of the first
voltage rail and the second voltage rail.