Patent ID: 7755428
Filing Date: 2010-07-13
Classification: H03F

Abstract:
1. An amplifying circuit, comprising: an output stage circuit provided with a first output transistor for controlling a conducting current based on a first control signal and a second output transistor for controlling a conducting current based on a second control signal, the transistors causing the output stage circuit to operate as a class AB push-pull circuit; and a pre-stage circuit, in which the first control signal and the second control signal are generated in accordance with an input signal; wherein, the first control signal causes the first output transistor to operate in class AB mode in a first ON period set in accordance with a positive signal period in which the input signal is positive, and places the first output transistor in a cutoff state in a first OFF period set in accordance with a negative signal period in which the input signal is negative; and the second control signal causes the second output transistor to operate in class AB mode in a second ON period set in accordance with the negative signal period, and places the second output transistor into a cutoff state in a second OFF period set in accordance with the positive signal period, the pre-stage circuit comprising: