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:
Nov. 12, 2019
Filed:
Apr. 27, 2017
Applicant:
Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;
Inventors:
Masakazu Kishi, Kawasaki, JP;
Hajime Kubota, Kawasaki, JP;
Masayuki Itoh, Kawasaki, JP;
Yoshinori Mesaki, Yokohama, JP;
Assignee:
FUJITSU LIMITED, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B 5/32 (2006.01); H03L 5/00 (2006.01);
U.S. Cl.
CPC ...
H03B 5/32 (2013.01); H03L 5/00 (2013.01); H03B 2200/0018 (2013.01); H03B 2200/0034 (2013.01); H03B 2200/0046 (2013.01);
Abstract
A crystal oscillator includes a crystal resonator; an inverting amplifier configured to be coupled between a pair of excitation electrodes of the crystal resonator; and a control circuit configured to initiate an alarm and raise gain of the inverting amplifier in a case where an index value for representing oscillation amplitude of the crystal resonator in an oscillation state is equal to or lower than a reference value.