Patent ID: 8022736

Claim:
A line driver for generating a predetermined output voltage on an output node of an integrated circuit when the output node is connected to a transmission line having a first resistance value, the line driver comprising: means for generating an output control signal in response to a digital data signal, a first stage transistor for generating a first current at an internal node in response to the output control signal, a second stage transistor for generating a second current at the output node in response to the output control signal, wherein the second stage transistor is constructed such that the second current is a predetermined number times larger than the first current, a bridge resistor connected between the internal node and a common mode voltage; a first trimmable resistive circuit connected between the internal node and the output node; and a control circuit for adjusting a total output resistance value of the line driver by controlling a series voltage across said first trimmable resistive circuit between the internal node and the output node, wherein the control circuit includes: a second trimmable resistive circuit for generating a replica series voltage on a predetermined node; and means for comparing the replica series voltage with first and second node voltages, and for generating one or more control signals until the replica series voltage is between the first and second node voltages, wherein said one or more control signals are simultaneously transmitted to both the first trimmable resistive circuit and the second trimmable resistive circuit, and wherein the first and second node voltages are generated such that, when the replica series voltage is between the first and second node voltages, the series voltage across the first trimmable resistive circuit is adjusted such that the total output resistance value is equal to the first resistance value of the transmission line.