Systems and methods for reducing the noise level in a multi-channel
digital audio system by staggering the timing of the pulse-width
modulation in the different channels and thereby reducing the magnitude
and increasing the frequency characteristics of the generated switching
noise. One embodiment comprises a multi-channel digital PWM amplifier in
which the timing signals used by each channel's modulator are staggered
to evenly space the switching edges of the generated PWM signals. An
additional, complementary delay is implemented in each of the channels to
equalize the total delay for each channel so that the outputs of the
channels are synchronized. The different channels may be implemented on
different chips, in which case the chips may be synchronized prior to
staggering the signals processed in each of the channels.