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.

Date of Patent:
Feb. 23, 2016

Filed:

Feb. 12, 2014
Applicants:

Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;

Fujitsu Semiconductor Limited, Yokohama-shi, Kanagawa, JP;

Inventors:

Hiroyuki Nakamoto, Kawasaki, JP;

Kazuaki Oishi, Yokohama, JP;

Tomokazu Kojima, Yokohama, JP;

Assignees:

FUJITSU LIMITED, Kawasaki, JP;

FUJITSU SEMICONDUCTOR LIMITED, Yokohama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L 7/00 (2006.01); H03K 17/22 (2006.01); H03K 3/037 (2006.01);
U.S. Cl.
CPC ...
H03K 17/223 (2013.01); H03K 3/0375 (2013.01); H03K 17/22 (2013.01);
Abstract

A power on reset circuit including: a startup circuit keeping an operation signal in an operating state during a power supply rises; a bias circuit keeping the operation signal in the operating state; a BGR circuit being activated during the operating state, and outputting a fixed voltage after a predetermined time elapses; a power supply divided voltage generation circuit outputting a reference voltage; an activation detection circuit generating a control signal which becomes inactive when a power supply rises and becomes active when the fixed voltage reaches a predetermined level; a comparator circuit outputting a power on signal and detecting as the power on signal when the reference voltage is greater than the fixed voltage; and a switch turning on and fixing an output of the comparator circuit to an inactive logical value while the control signal is inactive, and turning off while the control signal is active.


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