VOLTAGE-MODE DRIVER WITH PRE-EMPHASIS

摘要

A voltage-mode driver circuit supporting pre-emphasis includes multiple resistors, and multiple transistors operated as switches. Control signals operating the transistors represent a logic level of an input signal to the driver circuit. To generate a pre-emphasized output, the transistors are operated to connect a parallel arrangement of the resistors between output terminals of the driver and corresponding constant reference potentials. To generate an output in the steady-state, the transistors are operated to connect some of the resistors across the output terminals of the driver, thereby reducing the output voltage. A desired output impedance of the driver, and a desired level of pre-emphasis are obtained by appropriate selection of the resistance values of the resistors. The current consumption of the driver is less in the steady-state than in the pre-emphasis mode.