Browse Prior Art Database

Non Linear FET Driver for Transmission Line with Low Termination Impedance

IP.com Disclosure Number: IPCOM000056457D
Original Publication Date: 1980-Dec-01
Included in the Prior Art Database: 2005-Feb-14

Publishing Venue

IBM

Related People

Authors:
Buckley, M Prymak, R Zeidenbergs, J [+details]

Abstract

An FET driver with a non-linear impedance is connected by a transmission line to an FET receiver circuit that has a low termination impedance. Because the termination impedance is lower than the characteristic impedance of the line, it causes reflections on the line, but the reflections are controlled by the impedance of the driver, and the low impedance reduces power consumption. The non-linear impedance of the driver (as contrasted with the usual low impedance of a driver) is variable as the voltage on the line changes so that the waveform rises rapidly (low driver impedance at high voltage), but ringing is damped by the driver impedance as the line voltage rises (higher driver impedance at low driver voltage). The high impedance of the driver also permits a reduction in the area of the driver on a silicon chip.