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:
Sep. 23, 2003
Filed:
Nov. 09, 2001
James Charles Schmoock, Granite Bay, CA (US);
Jeffrey P. Kotowski, Nevada City, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A multiple over current protection circuit for regulating current through an analog switch coupled between a power supply and a load. In a first circuit, a comparator monitors a voltage drop across the analog switch. When the voltage drop exceeds a reference voltage, the comparator momentarily activates a first transistor and causes an amplifier to enter a current limiting mode. The activated first transistor causes the analog switch to momentarily turn off. In a second circuit, the comparator activates a second transistor. During the current limiting mode of the amplifier, a constant voltage is maintained at the source of the second transistor and the load side of the analog switch. A current source draws a current through the second transistor. Also, the current flowing through the analog switch tracks the current flowing through the second transistor.