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:
Apr. 08, 1997
Filed:
Sep. 12, 1995
Satoshi Matsuura, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
A differential amplifier having a largely variable range of output amplitude. The differential amplifier includes first and second transistors respectively having emitters connected to a first constant current source. A third transistor having a base and a collector connected to a base and a collector of the first transistor respectively. The differential amplifier further includes a fourth transistor having a base and collector connected to a base and collector of the second transistor respectively. The differential amplifier further includes resistors respectively connecting the collectors of the first and second transistors to a voltage source; and a second constant current source connected to emitters of the third and fourth transistors. An amplitude control circuit controls the current sources in response to an input signal so as to vary the output amplitude while maintaining the desired frequency characteristics of the differential amplifier.