Patent ID: 7250793

Claim:
A driving circuit for outputting a differential signal, comprising: an output circuit for outputting the differential signal according to a first voltage and a second voltage; a control signal generator, coupled to the output circuit, for generating the first voltage and the second voltage, comprising: a current mirror, comprising: a first transistor having a gate; a reference current generator, coupled to the gate of the first transistor, for providing a reference current; and a second transistor having a gate coupled to the gate of the first transistor and the reference current generator; a first conducting path, coupled to the gate of the first transistor, the gate of the second transistor and the reference current generator, for providing the first voltage to the output circuit according to the voltage of the gates of the first and second transistors; and a second voltage generator for generating the second voltage to the output circuit; and a switching circuit, coupled between the output circuit and the control signal generator, for controlling the coupling and decoupling relation between the output circuit and the control signal generator such that the differential signal representing logic high or logic low according to the coupling and decoupling relation between the output circuit and the control signal generator.