Patent ID: 6288592
Filing Date: 2001-09-11
Classification: H04L

Abstract:
A cable driver comprising:(a) an input port for receiving an input signal, comprising first and second input terminals;(b) an output port for transmitting an output signal on a transmission line, comprising first and second output terminals;(c) a first resistance and a second resistance for defining said output signal at said output port, said first resistance being coupled between a voltage source and said first output terminal and said second resistance being coupled between said voltage source and said second output terminal;(d) a plurality of switching stages, wherein each of said switching stages comprises a switch and a current source associated with said switch for producing a current, said current source being coupled to its associated switch for controlling the switching time of said associated switch and each of said switches being coupled to said output port, said plurality of switching stages including a first switching stage;(e) a plurality of delay stages for providing a delay time, wherein said first switching stage is coupled to said input port and the remaining switching stages are coupled in series, wherein one of said delay stages is coupled between each successive pair of said switching stages, such that each delay stage is coupled to a preceding switching stage and a succeeding switching stage, and wherein the delay time of each of said delay stages corresponds to the delay time of the other said delay stages, and wherein the current of each of said current sources corresponds to the current of the other said current sources and wherein the delay times and the currents are selected so that the rise and fall times of a first selected portion of said output signal exceeds a selected duration and a second selected portion of the output signal is substantially linear.