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:
Oct. 08, 2002
Filed:
Aug. 01, 2001
Atsushi Minegishi, Tokyo, JP;
Iwatsu Electric Co., Ltd., Tokyo, JP;
Abstract
An amplifying circuit with a level-shift circuit is disclosed. An amplifying unit includes two stages of differential amplifiers cascadedly connected. A differential amplifier of the first stage has a pair of differential input terminals. The differential amplifier of the last stage has a pair of differential output terminals. A level-shift circuit constituted of a couple of level-shifters is connected to the output terminals. The level-shift circuit level-shifts the DC level of the differential output from the amplifying unit. The level-shift circuit has a pair of output terminals to deliver the level-shifted differential output. A DC-dummy dummies the DC operation of the differential amplifier of the last stage. The DC-dummy has the power supply in common with the differential amplifier of the last stage. A level-shifter shifts the output level from the DC-dummy and delivers the level-shifted dummy output. The constitution of the level-shifter is the same as one of a couple of level-shifters in the level-shift circuit. An operational amplifier keeps a voltage of the level-shifted dummy output constant. Therefore, the operational amplifier supplies the voltage power in common to the differential amplifier of the last stage and the DC-dummy.