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:
Sep. 18, 2001
Filed:
Jun. 05, 2000
Shuji Shibuya, Kanagawa, JP;
Hisato Takeuchi, Kanagawa, JP;
Junichi Matsuura, Kanagawa, JP;
Yuichi Tateyama, Kanagawa, JP;
Takaharu Saeki, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A temperature compensating crystal oscillation device includes a constant voltage circuit (,) for outputting a predetermined voltage independent of the ambient temperature, a temperature sensor circuit (,) for outputting a voltage in proportion to the ambient temperature, and a control circuit (,) for receiving the constant voltage output from the constant voltage circuit (,) and the voltage output in proportion to the temperature from the temperature sensor circuit (,) and for generating a control voltage (Vc) used for compensating a temperature characteristic of a quartz oscillator in the entire range of the ambient temperature through polygonal lines approximation of a negative cubic curve by using continuous lines. Furthermore, the crystal oscillation device includes a VCXO (,) whose oscillation frequency is controlled to be a predetermined value by the control voltage (Vc), and a ROM/RAM circuit (,) for storing temperature compensating parameters used for compensation of a temperature characteristic of the control voltage (Vc) for optimizing the oscillation frequency of the VCXO (,).