Patent ID: 7301393

Claim:
An electronic class-D amplifier including: an amplifier input to which an amplifier input signal may be applied, an amplifier output which may produce an amplifier output signal, an output switching stage, a pulse width modulator which includes an oscillator and a first comparator, at least one servo-loop amplifier, an input signal processor which processes and modifies the input amplifier signal, wherein an output signal of the oscillator produces a carrier reference signal which includes at least positive and negative time derivative components, which are modulated by an output of the input signal processor which is applied to a modulation input of the oscillator, whereby at least the symmetry of the carrier reference signal is modulated, and the oscillator includes at least one integrating element, the amplifier input being connected to an input of the servo-loop amplifier, the servo-loop amplifier also including at least one integrating element, the amplifier input also being connected to a modulation input of the input signal processor, an output of the servo-loop amplifier being connected to an input of the pulse width modulator, an output of the pulse width modulator being connected to an input of the output switching stage, and an output of the output switching stage being connected to the amplifier output, wherein a negative feedback path connects an output of the output switching stage to an input of the servo-loop amplifier.