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. 20, 1996
Filed:
Feb. 14, 1994
James A Heaney, Durham, NC (US);
Todd M Rasmus, Cary, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A local area network (LAN) interface port with a simple overcurrent protection circuit which isolates the power supply connection for the port from fault conditions on the LAN. The circuit has a normally-on field effect pass transistor in line with the load terminal. The pass transistor shuts off when a fault condition is detected. Such a condition is detected when the voltage across a sense resistor becomes greater than the voltage across a reference resistor. A current mirror is made up of a transistor array and the sense and reference resistors. The current mirror compares the two voltages, and a bipolar transistor switches the gate voltage of the pass transistor on when the fault condition is detected. The design is particularly useful with the LAN system specified in ANSI/IEEE Standard 802.3, commonly known as Ethernet.