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:
Dec. 04, 1990
Filed:
Sep. 05, 1989
Arthur J Edwards, Hoffmann Estates, IL (US);
Randall C Gray, Tempe, AZ (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
An automobile alternator regulator integrated circuit having a voltage-supply or -sense node (6) for connection to an external voltage, and a voltage clamp comprising: a pnp bypass transistor (Q1) having a base electrode, an emitter electrode coupled to the node and a collector electrode coupled to ground; a resistor (R1) connected between the base electrode and the node; a Zener diode (Z1-Z4) connected between the base electrode and ground for enabling the bypass transistor when the voltage at the node exceeds a predetermined value, whereby the voltage at the node is clamped to a voltage no greater than the predetermined value; and a fuse (F1) connected between the node and the emitter electrode so as to provide a subsequently identifiable cause of failure if the fuse becomes blown due to excess voltage while allowing subsequent operation of the integrated circuit if the clamp means fails but another part of the integrated circuit remains functional.