Patent ID: 8547140

Claim:
An apparatus comprising: a first node configured to receive a voltage reference; a first current path comprising: a first MOS transistor of a first semiconductor type, wherein the first MOS transistor is a replica of a driver transistor of the first semiconductor type, wherein the driver transistor is configured to pull up or pull down a non-inverted or inverted signal of a differential signal for a driver, wherein the driver transistor is configured to switch between an on state and an off state for data transmission; a plurality of resistors arranged in series with the first MOS transistor, wherein the plurality of resistors have a first end, a second end, and an intermediate node; and an operational amplifier having a first input, a second input, and an output, wherein the first input is electrically connected to the first node, wherein the second input is electrically connected to the intermediate node, wherein the output is electrically connected to the gate of the first MOS transistor and is provided as a first bias voltage, wherein the operational amplifier is in a closed-loop feedback path such that a voltage at the first node is substantially equal to a voltage at the intermediate node; wherein a gate voltage of the driver transistor for the on state corresponds to the first bias voltage.