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:
Jun. 06, 2006
Filed:
Jun. 01, 2004
Hiroshi Tanigawa, Tsurugashima, JP;
Shuichi Nakamura, Tsurugashima, JP;
Satoru Yamane, Tsurugashima, JP;
Hiroshi Tanigawa, Tsurugashima, JP;
Shuichi Nakamura, Tsurugashima, JP;
Satoru Yamane, Tsurugashima, JP;
Toko, Inc., Tokyo, JP;
Abstract
Disclosed is a variable output-type constant current source circuit capable of varying its output current in a stepwise manner without the complication in circuit configuration and the increase in size of a semiconductor circuit board for incorporating the circuit therein. The constant current source circuit comprises a first self-biasing type constant current circuitconfigured such that transistors M, Mare operable to cooperatively supply a given voltage across a resistor RS to generate a stabilized current I. In order to vary the output current, the constant current source circuit includes a switching circuit(transistor M) connected in series to a series circuit connecting in series the transistor Mand the resistor RS, and a second constant current circuitconnected in parallel to a series circuit connecting in series the transistor M, the resistor RS and the transistor M. The second constant current circuitis also configured to serve as an activation circuit for the first constant current circuit