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. 22, 1991
Filed:
Dec. 06, 1989
Yoshinori Yoshikawa, Kawasaki, JP;
Kunihiko Gotoh, Tama, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A constant current source circuit includes a current mirror circuit supplying a load circuit with an output current which is regulated on the basis of a reference current, a transistor having an emitter, a collector connected to a first power source line, and a base coupled to the current mirror circuit, and a resistor coupled between the emitter and base. The reference current passes through the resistor. A current control circuit controls a current directed to a second power source line in accordance with a bias voltage. The above current consists of the reference current and a collector current passing through the transistor. A bias circuit having a current path derives the bias voltage from a current passing from the first power source line to the second power source line through the current path.