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:
Sep. 22, 1998
Filed:
Jan. 14, 1997
Rohm Co., Ltd., Kyoto, JP;
Abstract
A differential amplifier circuit which has a pair of transistors capable of differential operation with a predetermined bias voltage and a predetermined bias current being set for the base is combined with a dummy circuit having a transistor with a substantially equivalent load to one member of said transistor pair and which is biased in an equivalent relationship to said one transistor, a current mirror in which the base of an input transistor is not diode connected but connected to the base of an output transistor and supplied at the collector or emitter with a drive current flowing to the base of said transistor in said dummy circuit and in which said output transistor supplies each of the bases of said pair of transistors with said bias current which is substantially equal to the current flowing to the base of said transistor in said dummy circuit, and a control circuit that is connected to the base of said transistor in said dummy circuit and which receives the base voltage of said transistor in said dummy circuit and said predetermined bias voltage to maintain the base of said transistor in said dummy circuit at said predetermined bias voltage.