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. 27, 2015
Filed:
May. 15, 2012
Takehisa Sato, Kanagawa, JP;
Takehisa Sato, Kanagawa, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
A power source circuit includes a voltage converter circuit and a control circuit that includes a voltage divider circuit and a protective circuit. The protective circuit includes a first oxide semiconductor transistor in which an off-state current is increased as temperature is increased, a capacitor that accumulates the off-state current as electric charge, a second oxide semiconductor transistor, and an operational amplifier including a non-inverting input terminal to which a reference voltage is input. The first oxide semiconductor transistor is provided near the voltage converter circuit or an element that generates heat in the control circuit.