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:
Jan. 27, 2015
Filed:
Apr. 17, 2012
Applicant:
Hiroyuki Tomatsu, Kanagawa, JP;
Inventor:
Hiroyuki Tomatsu, Kanagawa, JP;
Assignee:
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 3/22 (2006.01); H01L 27/02 (2006.01); H01L 27/06 (2006.01);
U.S. Cl.
CPC ...
H01L 27/0266 (2013.01); H01L 27/0688 (2013.01);
Abstract
To provide a protection circuit having a small area, redundancy, and small leak current. In the protection circuit, a plurality of nonlinear elements is provided so as to overlap with each other and so as to be electrically connected in series. At least one nonlinear element in the protection circuit is a diode-connected transistor including an oxide semiconductor in its channel formation region. The other nonlinear element is a diode-connected transistor including silicon in its channel formation region or a diode including silicon in its junction region.