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. 06, 2002
Filed:
Jul. 27, 2000
Peter Braun, Buehlertal, DE;
Robert Kern, Buehlertal, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A polarity reversal protective circuit for an electronic power output stage that can be driven via a drive circuit is described. In the case of an incorrect polarization of a supply voltage, power FETs are used in at least one supply terminal to interrupt a connection of the wrongly applied supply voltage to the drive circuit and the power output stage. A definite polarity reversal protection is obtained using a circuit that is improved with respect to cost and space requirement. A single N-channel power FET is looped, with its source-drain path, into the positive supply terminal of the supply voltage. The source terminal of the N-channel power FET is connected with the positive supply terminal. The gate terminal of the N-channel power FET is connected to a collector of a PNP transistor, which is additionally connected to an output of the drive circuit via a current-limiting resistor. An emitter of the PNP transistor is connected—via a diode that is conductive when the supply voltage is wrongly applied—to the positive supply terminal. The base of the PNP transistor is connected—via a base resistor—to a negative (ground) supply terminal of the supply voltage.