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. 27, 2007
Filed:
Sep. 21, 2005
Vijayalakshmi Devarajan, Dallas, TX (US);
John H. Carpenter, Jr., Rowlett, TX (US);
Benjamin Lee Amey, Allen, TX (US);
Vijayalakshmi Devarajan, Dallas, TX (US);
John H. Carpenter, Jr., Rowlett, TX (US);
Benjamin Lee Amey, Allen, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A thermal shutdown circuit for protecting a main FET that conducts a load current ILOAD. A reference circuit provides a temperature current proportional to temperature. A thermal sensor circuit has a resistor and generates an output signal signaling thermal shutdown when the voltage generated across the resistor by the temperature current exceeds a predetermined value. A sense FET having a size smaller than the main FET conducts a sense current ISENSE proportionately smaller than ILOAD. A current mirror mirrors a scaled current proportional to ISENSE to be conducted through the resistor, the scaled current being scaled so as to cause the voltage generated across the resistor to exceed the predetermined value when ILOAD exceeds a predetermined value.