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. 11, 2007
Filed:
Jul. 14, 2005
Hisato Takeuchi, Yokohama, JP;
Keigo Shingu, Suginami-ku, JP;
Takashi Ootsuka, Yokohama, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a voltage controlled oscillator including an amplifier, a feedback circuit and a crystal oscillator, two MOS transistors M, Mare connected for use as variable capacity elements for the frequency adjustment of the voltage controlled oscillator. Drains of the MOS transistors M, Mare respectively connected to an XT terminal and an XTB terminal of the crystal oscillator. Sources of the MOS transistors M, Mare made common and connected to a grounding terminal via a capacitor C. Gates of the MOS transistors M, Mare made common, and an added voltage signal of a temperature compensating signal voltage and an external frequency control signal voltage is applied to the common gate terminals of the MOS transistors to thereby perform the frequency control of the oscillator.