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:
Jul. 08, 2003
Filed:
Aug. 21, 2001
Takeshi Nakamura, Uji, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
An amplifier circuit includes an input terminal and a first amplifier. A node between the input terminal and the first amplifier is connected to a first input of a comparator circuit. A node between a second amplifier at the final stage and an output terminal is connected to a second input of the comparator circuit. The output of the comparator circuit is connected to a signal blocking circuit. The comparator circuit compares voltages of two input signals. When the output voltage of the second amplifier falls below the input voltage of the first amplifier, the signal blocking circuit is switched from an ON state to an OFF state. Thus, the second amplifier can be protected from excessive current caused by short-circuiting of the output terminal, without deteriorating the dumping factor and the transient characteristic. Even when the signal level is so low that only a minute current flows, it is possible to detect short-circuiting of the output terminal and to protect the second amplifier.