Browse Prior Art Database

Method for active voltage adjustment in-line driver interfaces

IP.com Disclosure Number: IPCOM000009384D
Publication Date: 2002-Aug-20
Document File: 3 page(s) / 101K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for active voltage adjustment in-line driver interfaces. Benefits include improved signal quality, improved reliability, and improved design simplification.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Method for active voltage adjustment in-line driver interfaces

Disclosed is a method for active voltage adjustment in-line driver interfaces. Benefits include improved signal quality, improved reliability, and improved design simplification.

Background

              Integrated circuit (IC) solutions are positioning designs to include as much circuitry as possible within a single chip. A penalty is paid in the area of the integration of line drivers into the IC. When the line driver is integrated into the primary VLSI device, keeping the line driver pins in close proximity to the physical connector that the signals are to be transmitted on is nearly impossible. In addition, the voltage levels that may be transmitted through the lines (cables connected to the connector) are tightly defined by external specifications. The IC is limited to producing no more than the maximum specified voltage. Yet, because the driver can no longer be guaranteed to reside physically adjacent to the connector (where the voltage is measured by specification), voltage losses occur as the signal traverses the printed wiring board (PWB) from the integrated IC to the connector. This PWB line length can be from 2 inches to 12 inches. Voltage can be lost so that the board design may not be able to drive the external cable with enough voltage to meet maximum cable lengths.

Description

              The disclosed method is active voltage adjustment in-line driver interfaces. The method includes sense circuit at the physical connector location. The result of this circuit is fed back to the line driver source so the line driver can adjust its output voltage to provide the correct specification voltage at the connector.

              The line driver is not in close proximity to the connector (see Figure 1). At the connector, a sense line is added to the design. This sense line feeds into a circuit that can measure the peak voltage of the signal at the connector, and adjust the voltage to be maximized through a feedback adjustment line (Adj) back to the line driver.

              Vol...