Patent ID: 7378904

Claim:
An audio amplifier, comprising: difference circuitry, for generating a difference signal responsive to an input signal and a feedback signal; a first comparator, for generating first pulse-width-modulated output pulses responsive to a comparison of the difference signal and a periodic reference waveform; a second comparator, for generating second pulse-width-modulated output pulses responsive to a comparison of the difference signal and a periodic reference waveform, the second pulse-width-modulated output pulses complementary to the first pulse-width-modulated output pulses; a power stage, for driving an amplifier output responsive to the first and second pulse-width-modulated output pulses; a loop filter for filtering a signal corresponding to the amplifier output to produce the feedback signal; and common mode ramp voltage circuitry, having an output coupled to inputs of the first and second comparators, for generating a common mode voltage of a first level in a muted mode, and for ramping the common mode voltage from the first level to a zero level responsive to a transition from the muted mode to an unmuted mode.