Patent ID: 7227408

Claim:
An electronic class-D amplifier including an amplifier input adapted to receive an amplifier input signal, an amplifier output adapted to produce an amplifier output signal, an output switching stage, a pulse width modulator including an oscillator and a first comparator, at least one servo-loop amplifier, having an integrating feed forward transfer function, the amplifier input being connected to an input of the servo-loop amplifier, characterised in that there is provided a sample and hold element which includes a sample input and a control input, wherein the sample and hold signal is applied to the control input, and the sample and hold element holds the value of the last sampled value of the signal at the sample input when a hold command signal is applied to the control input, and this held value is applied to an output of the sample and hold element, the amplifier input being further connected to a first input signal processor which processes the amplifier input signal, wherein a first output of the oscillator is adapted to produce a carrier reference signal, an output of the servo-loop amplifier is connected to the sample input of the sample and hold element, the output of the oscillator is connected to the control input of the sample and hold element, an output of the first input signal processor is connected to an input of the pulse width modulator, an output of the pulse width modulator is connected to an input of an output switching stage, and an output of the output switching stage is 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.