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:
May. 13, 1986
Filed:
Oct. 12, 1984
Gerhard Krumrein, Neuenstadt, DE;
TELEFUNKEN electronic GmbH, Heilbronn, DE;
Abstract
A protection circuit for an integrated circuit that is connected across a power source includes a first transistor and a zener diode or equivalent circuit arrangement for causing the first transistor to conduct if the integrated circuit receives an excessive voltage from the power source. A measuring resistor is connected to the emitter of the first transistor, and a voltage drop appears across the measuring resistor if the first transistor conducts. A comparator is provided to compare the voltage across the measuring resistor to a reference voltage. The output of the comparator drives the base of a second transistor, the emitter of which is connected to the collector of the first transistor and the collector of which is connected to the base of the first transistor. Current through the second transistor renders the first transistor more conductive.