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:
Aug. 31, 1999
Filed:
Nov. 06, 1997
Mark Covaro, Sunol, CA (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
A low voltage high current bi-directional termination voltage regulator for use in a bus termination circuit in a repeater stack is disclosed that includes an operational amplifier, a bipolar transistor current source circuit, and a bipolar transistor current sink circuit. The operational amplifier is configured to source current to a first node when the output voltage at a second node is pulled below a nominal termination voltage and configured to sink current from the first node when the output voltage at the second node is pulled above the nominal termination voltage, the second node being connected to a termination load. The bipolar transistor current source circuit is configured to source current to the second node when the operational amplifier sources current to the first node so that the output voltage at the second node is pulled up as a result of the current sourced by the bipolar transistor current source circuit through the second node to the termination load. The bipolar transistor current sink circuit is configured to sink current from the second node when the operational amplifier sinks current from the first node so that the output voltage at the second node is pulled down as a result of the current sinked by the bipolar transistor current source circuit through the second node from the termination load. Thus, the output voltage at the second node is maintained at the nominal termination voltage.