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. 09, 2004
Filed:
Aug. 29, 2002
Richard Frank, Longmont, CO (US);
Denis Michel Darmon, Longmont, CO (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A circuit is arranged to provide a thermal shutdown signal in response to an overtemperature condition. The thermal shutdown circuit is typically implemented in the same die as the circuitry that is to be protected. The thermal shutdown circuit provides a first current in response to a change in temperature when a VBE associated with a transistor decreases below a predetermined level. The first current is mirrored to provide a scaled current. A thermal shutdown signal is activated when the scaled current becomes greater than a reference current. The first current is increased in response to the activated thermal shutdown signal such that the thermal shutdown circuit is deactivated at a temperature that is lower than the temperature at which the circuit is activated. The thermal shutdown circuit is deactivated when the temperature of the die decreases.