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. 21, 2001
Filed:
Nov. 19, 1999
Kazuya Yamamoto, Tokyo, JP;
Akira Inoue, Tokyo, JP;
Satoshi Suzuki, Tokyo, JP;
Tomoyuki Asada, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Toyko, JP;
Abstract
While minimizing any increase in chip size and without incurring a loss in performance or operating characteristic under normal operating voltage conditions, a power amplifier protection circuit effectively prevents breakdown of power amplifying transistors resulting from output load fluctuations during operation with an overvoltage supply. The protection circuit includes a gate circuit electrically connected between the collector and base of at least the last-stage transistor in a power amplifier including transistors connected in stages. The gate circuit passes a feedback current to the base electrode of the protected transistor when a voltage exceeding a specific level is applied to the collector of the protected transistor.