Patent ID: 7834693

Claim:
A circuit, comprising: a class AB input stage circuit, for receiving an input signal and generating an inner signal according to the input signal; and a class AB output stage circuit, coupled to the class AB input stage circuit, comprising: a biasing circuit, for generating a first biasing signal and a second biasing signal according to the inner signal; and an output circuit, coupled to the biasing circuit, for generating an output signal according to the first biasing signal and the second biasing signal; wherein a voltage difference between the first biasing signal and the second biasing signal is corresponding to the input signal; and the biasing circuit comprises: a first current source, for providing a first predetermined current; a second current source, for providing a second predetermined current; and a resistor unit, coupled between the first current source and the second current source, for generating the first biasing signal and the second biasing signal according to the first predetermined current and the second predetermined current.