The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1999
Filed:
Sep. 13, 1996
Alan J Baker, Loveland, CO (US);
Marc H Ryat, Santa Clara, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An adaptive cable equalizer is provided with a simple architecture, wherein a single control structure: controls the adaptation of the filter for compensating for cable length while simultaneously compensating for process and temperature variations; optimizes the SNR at any cable length by controlling biasing current sources; and uses a two-stage architecture which eliminates start-up problems and optimizes output levels to obtain optimal dc restoration while simultaneously allowing for independent optimization of the output levels of the recovered data in accordance with other requirements as desired. An analog adaptive equalizing filter is used for accurately synthesizing the inverse transfer function of cables of variable lengths. Data rates up to and beyond 400 Mbps are supported and the adaptive behavior automatically compensates for different cable lengths as well as process variations (with respect to the process(es) used for fabricating the equalizer in a monolithic form) and temperature variations.