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:
Feb. 10, 2004
Filed:
Sep. 10, 2002
Shinji Saito, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
By a gain control circuit which has: a first differential input circuit comprising a differential pair of transistors Tr and Tr in which transistors Tr and Tr connected to diodes are inserted; a second differential input circuit comprising a pair of the transistor Tr and a transistor Tr ; and a current source circuit comprising a transistor Tr and an emitter resistor R , and to which first to third individual control input signals VCLS to VCLS each having a predetermined inclination and an offset value, obtained by shifting the level of a control input signal VCNT are supplied, gain control signals VAGC having a linear characteristic, a monotone increase characteristic of which curve opens upwards, and a monotone increase characteristic of which curve opens sharply upwards are supplied in accordance with a monotone increase region of which curve opens upwards, a linear region, and a monotone increase region of which curve opens downwards, respectively, of a differential pair of transistors Tr and Tr and a differential pair of transistors Tr and Tr at the second stage of a differential amplification circuit.