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. 20, 2005
Filed:
Nov. 17, 2003
Takuma Ishida, Takatsuki, JP;
Taku Kobayashi, Suita, JP;
Keiichi Fujii, Kusatsu, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An AGC circuit, which does not require any signal integration circuit comprised of a capacitor and a resistor, is provided. To achieve the above object, when amplifying or attenuating input signal by a variable gain control circuit controlled by the gain control voltage, output signal of the variable gain amplifier circuit is rectified by a rectification circuit, the output signal of the rectification circuit is compared to an arbitrary set voltage by a voltage comparator. The up-count operation and the down-count operation of the up/down counter is controlled to changeover by the output signal of the voltage comparator, and a voltage corresponding to the count value of the up/down counter is output from the D/A conversion circuit. Thus, gain control voltage corresponding to the voltage output from the D/A conversion circuit is supplied to the variable gain amplifier circuit.