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:
May. 17, 2011
Filed:
Sep. 29, 2009
Tomoaki Nishi, Nagaoka, JP;
Tomoaki Nishi, Nagaoka, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Sanyo Semiconductor Co., Ltd., Gunma, JP;
Abstract
A constant-current circuit comprising: a temperature-compensation circuit to output a temperature-compensated first current; and a current-supply circuit to supply a second current to the temperature-compensation circuit, the temperature-compensation circuit including a voltage-multiplication circuit including a first transistor to generate a base-collector voltage obtained by multiplying a base-emitter voltage by a predetermined ratio, a second transistor identical in conductivity type and substantially equal in base-emitter voltage to the first transistor, a first resistor having two ends connected to a first-transistor collector and second-transistor base, respectively, and a second resistor having two ends connected to first and second-transistor emitters, respectively, the first current being output according to a second-transistor collector current, the second current being supplied to a connection point between a second-transistor base and the first resistor, to generate between both ends of the first resistor a voltage varying substantially in proportion to temperature.