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:
Jan. 14, 2003
Filed:
May. 25, 2001
Rikoku Nakamura, Nishitokyo, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
Disclosed is an integrated voltage-controlled crystal oscillator intended to present the conditions for circuit constants in an oscillator circuit that can improve the oscillator's frequency tuning range with respect to the variable capacitance range of a variable-capacitance element. The voltage-controlled crystal oscillator comprises a crystal, an amplifier, and a load capacitor, wherein the load capacitor includes a voltage-controlled variable-capacitance element integrated on a semiconductor substrate and a DC cut capacitor element connected in series with the voltage-controlled variable-capacitance element, and the DC cut capacitor element has a capacitance value (Ccut) whose ratio to a maximum capacitance value (Cvmax) of the voltage-controlled variable-capacitance element (Ccut/Cvmax) is more than 0.5 and not more than 10.