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, 2007
Filed:
Jun. 26, 2003
Hideaki Watanabe, Kasugai, JP;
Hideaki Watanabe, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A clock multiplication circuit simple in configuration, easy to adjust the characteristics thereof, and capable of shortening lockup time. The circuit delivers an output clock signal at a frequency that is a multiple of the frequency of a reference clock signal as inputted. A counter counts the number of rising edges of the output clock signal existing during a High level period of the reference clock signal, delivering a count value CN. A subtracter subtracts the count value from a reference value BN, delivering a difference value DN. An adder adds the difference value to a preceding integrated value, calculating a new integrated value. A DA converter delivers the analog control voltage corresponding to the integrated value. A VCO delivers the output clock signal at a frequency corresponding to the analog control voltage. The frequency of the output clock signal is controlled such that DN=BN−CN=0.