Patent ID: 6448815
Filing Date: 2002-09-10
Classification: H04L

Abstract:
A differential data communication system comprising:a differential driver for generating a differential data signal from a binary data signal, said differential data signal for transmission over a communication medium; a pull-up resistor coupled between said differential driver and a first voltage source for controlling an upper voltage level of said differential data signal; and a pull-down resistor coupled between said differential driver and a second voltage source for controlling a lower voltage level of said differential data signal; wherein said pull-up and pull-down resistors have variable resistance values that are programmable to respectively vary a first voltage difference across the pull-up resistor and a second voltage difference across the pull-down resistor, the first voltage difference and the second voltage difference controlling the upper voltage level and the lower voltage level of the differential data signal respectively, for maintaining said upper and lower voltage levels for optimal data transmission of said differential data signal by said differential driver over said communication medium.