Patent ID: 6124757
Filing Date: 2000-09-26
Classification: H03F

Abstract:
An amplifier comprising input signal processing means having an input and an output, and an output stage coupled to the output of the input signal processing means, the signal processing means comprising a modulator for producing an input signal applied to the output stage, the output of the input signal processing means producing an input signal for application to the output stage, and the output stage comprising switching means having an output for outputting an output signal of the amplifier, the amplifier further comprising a power source coupled to power said output stage, and noise reduction means coupled to said power source and to said input signal processing means, wherein said noise reduction means is arranged to apply any noise signals from the power source to the input signal processing means such that said input signal applied to the output stage is modulated by the noise signals and thereby is arranged to cancel said noise signals in the output stage and said noise reduction means is arranged to apply said power signals to said modulator and wherein said noise reduction means is arranged to apply clock signals to said modulator, the clock signals being frequency modulated by signals from the power source.