Patent ID: 7288967

Claim:
A differential output driver, comprising: a driver including: a differential output portion comprising first and second on-die termination resistors connected to an inverted output signal generation terminal and an output signal generation terminal, respectively to terminate an inverted output signal and an output signal, a first driver connected to the inverted output signal generation terminal to generate the inverted output signal in response to an input signal, and a second driver connected to the output signal generation terminal to generate the output signal in response to an inverted input signal, an inverted output signal drive variable portion connected in parallel to the first driver to vary a driving capability of the first driver in response to a first control signal, and an output signal drive variable portion connected in parallel to the second driver to vary a driving capability of the second driver in response to a second control signal; and a controller for detecting voltage differences between a reference voltage and each of the inverted output signal and the output signal, detecting a voltage difference between the voltage differences to generate an average error value, and generating the first and second control signals in response to the average error value.