Patent ID: 7777564
Filing Date: 2010-08-17
Classification: H03F

Abstract:
1. An amplifier using sigma-delta modulation, comprising: a sigma-delta modulating circuit, for generating two input voltages according to two input signals or one single-ended signal; a power stage circuit, coupled to the sigma-delta modulating circuit, for providing two output voltages according to the two input voltages or an error adjusting voltage; a pair of feedback components, comprising a first feedback component coupled between a first input terminal of the sigma-delta modulating circuit and a first output terminal of the power stage circuit and a second feedback component coupled between a second input terminal of the sigma-delta modulating circuit and a second output terminal of the power stage circuit, wherein a mismatch error exists between the first feedback component and the second feedback component; an error suppressing circuit, coupled to the sigma-delta modulating circuit and the power stage circuit, for providing the error adjusting voltage according to the two input voltages; and a selecting circuit, for outputting the two input voltages to the power stage circuit when the two input voltages correspond to different logic levels and for outputting the error adjusting voltage to the power stage circuit to suppress the mismatch error between the first feedback component and the second feedback component when the two input voltages correspond to an identical logic level.