Patent ID: 7332962
Filing Date: 2008-02-19
Classification: H03F,H03K

Abstract:
1. A filterless audio power amplifier for processing an input audio signal, the filterless audio power amplifier outputting a pair of differential outputs for driving a load impedance, comprising: an error amplifier, the input audio signal coupled to the error amplifier, first and second wave generators, generating first and second reference waves; a first comparator, coupled to the error amplifier, the first comparator being responsive to the first reference wave and the input audio signal; a second comparator, coupled to the error amplifier, the second comparator being responsive to the second reference wave and the input audio signal; a control logic unit, receiving outputs of the first and second comparators and further a third reference signal, the control logic unit resulting pulses in the pair of differential outputs in response to the third reference signal and a cross relationship between the input audio signal and the first and second reference waves, wherein pulses of one of the differential outputs are not overlapped with pulses of the other of the differential outputs for eliminating common mode noises of the power amplifier; a switching unit, coupled to the control logic unit, the operation states of the switching unit being under control of the control logic unit, the switching unit outputting the differential outputs; and a feedback unit, feed backing the differential outputs to the error amplifier, the error amplifier correcting the differential outputs in response to the input audio signal.