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. 10, 1985
Filed:
Sep. 01, 1982
Kazuo Kuroki, Tokyo, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
A highly stable, tunable oscillator circuit includes a crystal oscillator providing a reference pulse signal of frequency fcry, a voltage-to-frequency converter responsive to a control voltage vc for providing a control pulse signal of frequency fv substantially lower than fcry, and a flip-flop circuit receiving the reference and control signals and providing a negative going pulse signal synchronized with the reference signal and having a frequency fv and a pulse width equal to l/fcry. The signal provided by the flip-flop circuit and the complement of the reference signal are received by a NAND gate which periodically removes a pulse from the reference signal at intervals of l/fv and provides a resulting signal having a frequency of (fcry).sup.2 /(fcry+fv). The resulting signal is received by a frequency divider network which divides the frequency of resulting signal by an integer N and provides an output signal of a desired frequency. The output frequency is tunable by varying the frequency fv of the control signal by means of the control voltage vc. By selecting the frequencies of the reference and control signals such that fcry>>fv, a highly stable and smoothly tunable output signal is obtained.