Patent ID: 7965121

Claim:
A multifunctional output driver, comprising: a first differential unit coupled to a pair of transmission terminals, wherein the first differential unit is enabled in a first transmission mode to serve as a first driver for outputting an output signal compatible with a first transmission interface according to an input signal from a pre-driver; and a second differential unit coupled to the transmission terminals, wherein the second differential unit is disabled in the first transmission mode, and the first and second differential units are both enabled in a second transmission mode to serve as a second driver for outputting an output signal compatible with a second transmission interface according to the input signal from the pre-driver, and the second differential unit comprises: a first differential pair, coupled between a first node and the pair of transmission terminals; and a switching circuit to selectively disable the second differential unit according to an enabling signal; wherein the switching circuit comprises: a first switching device having a first terminal coupled to the pre-driver, a second terminal coupled to the first differential pair and a control terminal receiving the enabling signal; and a second switching device having a first terminal coupled to a voltage, a second terminal coupled to the second terminal of the first switching device and a control terminal receiving the enabling signal.