Patent ID: 8149024

Claim:
A dual function differential driver, comprising: a voltage mode differential driver portion, including a first, second, third and fourth transistor; a current mode differential driver portion, including the third transistor, the fourth transistor, a fifth transistor and a sixth transistor; and control circuitry connected to the voltage mode differential driver portion and the current mode differential driver portion to switch the dual function differential driver between operation as a voltage mode differential driver and operation as a current mode differential driver, or to disable the dual function differential driver; wherein the sources of the first and second transistors are switchable connected to a first voltage, the drain of the first transistor is connected to the drain of the third transistor and a first output line, the gate of the first transistor is connected to a first input line and the gate of the third transistor, the drain of the second transistor is connected to the drain of the fourth transistor and a second output line, the gate of the second transistor is connected to the gate of the fourth transistor and a second input line, the sources of the third and fourth transistors are switchably connected to a second voltage, the sources of the fifth and sixth transistors are connected to the first voltage, the gates of the fifth and sixth transistors are connected to the control circuitry, the drain of the fifth transistor is connected to the first output line and the drain of the sixth transistor is connected to the second output line.