DAC based driver with selectable pre-emphasis signal levels

摘要

A Transmit line driver with selectable pre-emphasis and driver signal magnitudes comprises a primary current driver for setting a primary current level and a pre-emphasis current driver that provides an additional amount of current that is superimposed with or added to the primary current level produced by the primary current driver. The pre-emphasis current has either negative or positive magnitude based upon a pre-emphasis signal logic state. A first current selection module defines a reference signal that is used to select the primary current driver output signal magnitude in a first current mirror, while a second current selection module is used to define a second reference signal that selects a pre-emphasis current driver signal magnitude in a second current mirror. Logic generates a binary signal to both the first and second current selection modules to select the current levels as well as the pre-emphasis signal.