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. 26, 2000
Filed:
Feb. 23, 1995
Norman E LeComte, West Greenwich, RI (US);
Eric K Larson, Narragansett, RI (US);
Thomas R Maher, Plainville, MA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A solid state power controller for switching power on and off to an electrical load which also serves as a circuit protection device protecting the load and/or the wire connected between the load output terminal of the controller and ground from thermal damage due to current overload is shown. Upon current overload the controller interrupts current to the load in a time inversely proportional to the square of the magnitude of the overload. The controller also limits the load current to a selected maximum level by controlling the drain-source resistance of power MOSFETs (PS1-7) used for switching power. A secondary interrupt is provided in the event that the junction temperature of the MOSFETs has risen to a selected maximum level. A thermal memory feature is included for both interrupt signals. The controller is controlled by a single on/off input line (COMMAND) and provides both a status (STATUS) and trip (TRIP) output line. The status can be configured to monitor load voltage or load current flow. The controller also can be configured to default to either an on or off state in the event the input line is disconnected. The controller is made so that it is externally programmable by providing selected external connection points (MPA, DTA, CLA1, CLA2) and choosing values of certain components (R.sub.cl1i, R.sub.cl2i, R.sub.ii, C.sub.ii, R.sub.mpi, C.sub.mpi) contained within the sealed controller package which results in a selected default condition.