Patent ID: 7940075

Claim:
A differential pre-emphasis driver comprising: a first current source supplying a first current; a second current source supplying a second current greater than the first current; a third current source supplying an average magnitude of the first and second currents; a fourth current source supplying an average magnitude of the first and second currents; a first select circuit including a first switching point connected to the first current source for switching into a first contact point or a second contact point; and a second select circuit including a second switching point connected to the second current source for switching into a third contact point or a fourth contact point, wherein the first contact point is connected to the third current source, a first output terminal and the third contact point, and wherein the second contact point is connected to the fourth current source, a second output terminal and the fourth contact point, wherein input terminals of the first and second current sources are connected to a power terminal, and output terminals of the first and second current sources are connected to the first select circuit and the second select circuit, respectively, and wherein output terminals of the third and fourth current sources are connected to a ground terminal, and input terminals of the third and fourth current sources are connected to the first output terminal and the second output terminal, respectively.