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:
Mar. 19, 1996
Filed:
Dec. 03, 1993
Russell A Hershbarger, Nevada City, CA (US);
Silicon Systems, Inc., Tustin, CA (US);
Abstract
A method and apparatus for providing a telephone line interface having selectable termination characteristics, such as impedance parameters, is provided using AC and DC transconductance loops. The present invention may be used with modem apparatus to provide regulatory compliance of line termination characteristics in multiple countries having different, even conflicting, standards or regulations. The preferred embodiment of the present invention uses a programmable switched capacitor filter to drive a transconductance driver that drives the telephone line. An AC transconductance loop controls AC transconductance characteristics, while a DC transconductance loop controls DC transconductance characteristics.