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:
Oct. 31, 2000
Filed:
Mar. 15, 1999
Mark J Mercer, Tucson, AZ (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A circuit (hereinafter 'auto-shutoff regulator') for regulating the power provided to a load automatically opens and closes a switch (hereinafter 'protection switch') to keep itself from being damaged by excessive power dissipation. The auto-shutoff regulator includes: (1) a shunt regulator coupled in parallel with the load and a power supply, and (2) another circuit (hereinafter 'overpower detector') that monitors the power dissipated by the shunt regulator. The overpower detector has a control line (hereinafter 'power shutoff line') that is coupled to the protection switch. When the power dissipated in the shunt regulator exceeds a predetermined threshold, the overpower detector drives a signal active on the power shutoff line, thereby to open the protection switch. Opening of the protection switch shuts off the supply of power to the shunt regulator, thereby to protect the shunt regulator from damage caused by excessive power dissipation. The overpower detector is also responsive to the voltage on a line coupled to the power supply. When the voltage falls below a threshold value, the overpower detector gets reset and drives the signal on the power shutoff line inactive, thereby to close the protection switch and restore the supply of power to the shunt regulator.