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. 16, 1999
Filed:
Jan. 14, 1998
Yasuhiro Sakurai, Tokorozawa, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
A temperature compensated crystal oscillator comprises a crystal oscillating circuit having an AT-cut crystal resonator; a linearizing correction circuit for transforming a temperature characteristic curve of an oscillating frequency of the crystal resonator into a straight line using a fixed coefficient common to all crystal resonators; a gradient correction circuit for eliminating the gradient of the linearized temperature characteristic of the oscillating frequency usmg a variable coefficient depending on the type of crystal resonator; and an f0 adjustment circuit for adjusting the gradient corrected temperature characteristic of the oscillating frequency so as to cause the oscillating frequency to lie within an allowable range. Thus, upon the temperature compensation of the oscillating frequency, there are separately performed the linearizing correction, the gradient correction and the f0 adjustment, to achieve a fast temperature compensation adjustment of the oscillating frequency.