Browse Prior Art Database

Level Regulated Balanced Line Driver

IP.com Disclosure Number: IPCOM000085015D
Original Publication Date: 1976-Feb-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Nestork, WJ: AUTHOR

Abstract

As circuit performance continues to push the subnanosecond area, the problem of distributing high-speed signals becomes a limiting factor.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 88% of the total text.

Page 1 of 2

Level Regulated Balanced Line Driver

As circuit performance continues to push the subnanosecond area, the problem of distributing high-speed signals becomes a limiting factor.

The circuit configuration shown which includes a biphase driver, balanced line receiver, and "back-to-back" Schottky diode clamps achieves the effect of line termination in subnanosecond circuits. By use of lines 1 and 2 the signal swing on the lines are reduced by a factor of 2 over conventional driver approaches. Although this concept requires two physical lines, it does not pose a problem when the number of lines available exceeds the number required to interconnect.

The back-to-back Schottky diodes (SD's) provide an effect at the end of the line "normalizing". Since the diodes are operated in their forward region (one "on" and one "off", DC and AC variations by the drivers or on the lines are quickly absorbed and a "smoothing" effect and "psuedo" termination is observed. As opposed to normal clamping approaches, the tying back of the diodes to the opposite lines provides a unique feedback system.

The operation of the circuit is as follows:

A and A are the out-of-phase and in-phase outputs of a current switch (clamped to provide a 0.4 voltage swing). When X moves in a positive direction, X moves in a negative direction. In this case Schottky diode SD1 conducts and will clamp in the forward direction. This forward voltage (~0.4v) is sufficient to turn T3 on and T4 off. SD1 will attempt to...