Patent ID: 7990178

Claim:
A driving circuit, comprising: a plurality of driving units each coupled between a first reference voltage and a second reference voltage, each driving unit comprising: a first bias component, having a first node coupled to the first reference voltage, and a second node for outputting a first bias current; a second bias component, having a first node for draining a second bias current, and a second node coupled to the second reference voltage different from the first reference voltage; a first metal-oxide-semiconductor (MOS) transistor, having a control node for receiving a first input signal, a first connection node coupled to the second node of the first bias component, and a second connection node coupled to a first output port of the driving circuit; a second MOS transistor, having a control node for receiving a second input signal, a first connection node coupled to the second node of the first bias component, and a second connection node coupled to a second output port of the driving circuit; a third MOS transistor, having a control node for receiving the second input signal, a first connection node coupled to the first output port of the driving circuit, and a second connection node coupled to the first node of the second bias component; and a fourth MOS transistor, having a control node for receiving the first input signal, a first connection node coupled to the second output port of the driving circuit, and a second connection node coupled to the first node of the second bias component; wherein the first MOS transistor, the second MOS transistor, the third MOS transistor, and the fourth MOS transistor are of a same conductive type; wherein the first output port is connected to a first cable having a first impedance matched with an impedance of the first bias component, and matched with an impedance of the second bias component; wherein the second output port is connected to a second cable having a second impedance matched with the impedance of the first bias component, and matched with the impedance of the second bias component; and a calibration unit, coupled to the driving units, for activating at least one of the driving units according to an output signal of one of the first output port and the second port of the driving circuit.