Patent ID: 7538611
Filing Date: 2009-05-26
Classification: H03F

Abstract:
1. A method for controlling an audio amplifier comprising: providing an input signal to a control stage of said audio amplifier; providing an output signal from said control stage to a positive output stage comprising a first switch and deriving a first voltage signal that is a first switched signal; providing a second output signal from said control stage to a negative output stage comprising a second switch and deriving a second voltage signal that is a second switched signal; and applying said first and second voltage signals to two inputs of a load; wherein said first and second voltage signals have pulsating voltage waveforms with opposite polarities and substantially equivalent amplitudes that are fed back to said control stage through a first feedback loop and a second feedback loop respectively, and the difference between said first and second voltages can be as high as the supply voltage of said audio amplifier; wherein said control stage contains a first comparator and two drivers, further wherein said first comparator's negative input terminal is connected with the positive part of said input signal and also connected with said first voltage signal through said first feedback loop, while said first comparator's positive input terminal is connected with the negative part of said input signal and also connected with said second voltage signal through said second feedback loop.