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:
Jul. 11, 2000
Filed:
Nov. 05, 1998
Hidehiko Kuroda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A current mirror circuit for outputting an output current in proportion to an input current, comprises a first transistor having a collector through which the input current flows, a second transistor having a base connected to a base of the first transistor and a collector through which the output current flows, a third transistor having a base connected to a collector of the first transistor, and an emitter through which a predetermined current flows, and a fourth transistor having a base connected to an emitter of the third transistor, and an emitter connected to the base of the first and second transistors. A variable current source is connected between an emitter of the third transistor and ground to cause the predetermined current to flow through the third transistor. The value of the predetermined current is variable. An input current detecting circuit is provided to detect the input current for controlling the variable current source so as to maintain the predetermined current in proportion to the input current.