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:
Jul. 28, 2009
Filed:
Sep. 01, 2005
Wataru Yokozeki, Kawasaki, JP;
Wataru Yokozeki, Kawasaki, JP;
Fujitsu Microelectronics Limited, Tokyo, JP;
Abstract
A frequency comparator compares frequencies of a reference clock and an output clock to output a frequency comparison signal. A frequency variable circuit is composed of a delay circuit, which has a plurality of inverting circuits connected in series, and a first selection circuit. The first selection circuit selects one of odd output signals outputted from odd-numbered inverting circuits, according to the frequency comparison signal to feedback the selected odd output signal to an input of the delay circuit as a feedback signal. A phase comparator compares phases of the reference clock and the output clock to output a phase comparison signal. A second selection circuit selects one of the odd output signals according to the phase comparison signal to output it as the output clock.