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:
Aug. 24, 1999
Filed:
Feb. 18, 1998
Brendan P Kelly, Stockport, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A power device circuit comprises a power semiconductor device (MPWR) in series with a load (LD) between a power supply line (1) and a return line (2), and a short-circuit detector (R1, R2, . . . R1', R2', . . . CP) for determining whether the load (LD) is short-circuit. The short-circuit detector examines the distribution of the supply-to-return voltage (Vbg) between the device (MPWR) and the load (LD) by comprising a comparator (CP) which has a first input (+) coupled to a series node (11) between the device and load and a second input (+) from circuit means (R1, R2, . . . , R1', R2', . . . ) coupled between the supply and return lines (1 and 2) to provide the second input (-) with a voltage supply signal (Vbg') which is a predetermined function of the supply-to-return voltage (Vbg). By so comparing the voltage (Vdl) at the series node (11) with the predetermined function of the supply-to-return voltage (Vbg), the detector (SC) provides an output signal (sc) indicating whether or not a short-circuit is present. Preferably pinch-resistors (R1,R2) or a voltage-clamp (ZD) are used with the circuit means (R1, R2, . . ., R1', R2', . . . ), so that the predetermined function of the supply-to-return voltage (Vbg) input to the comparator (CP) varies with the magnitude of the supply-to-return voltage (Vbg). By this means a lower percentage of the supply-to-return voltage (Vbg) can be input at a higher magnitude of the supply-to-return voltage (Vbg) than at a lower magnitude.