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, 2001
Filed:
Nov. 22, 1999
Toshiyuki Ozawa, Oota, JP;
Kazuhiro Kimura, Fukaya, JP;
Hiroyoshi Kaneyama, Nitta-gun, JP;
Takayuki Ohashi, Ora-gun, JP;
Akira Yamazaki, Kiryu, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
For frequency change, the VCO is controlled through a sub-charge pump circuit to make a determination as to whether or not a difference of dividing data between before and after the change is within a predetermined range. When it is determined that the difference is outside the predetermined range, the loop filer is forcibly charged in a charge time which is determined proportional to the difference in the dividing data, to thereby control an oscillation frequency of the VOC. A large VOC oscillation frequency change can be swiftly realized. Also, while the frequency change circuit is controlling the oscillation frequency, a time constant of the loop filter in the PLL circuit is preferably set at a small value, so that frequency change by the frequency change circuit can be swiftly achieved.