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. 29, 1997
Filed:
May. 13, 1996
Shigenori Yamaguchi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A frequency difference detection apparatus includes a first PLL, a second PLL, a first phase difference detection unit, a second phase difference detection unit, a phase difference processing unit, and a frequency difference detection unit. The first PLL detects a phase difference between an input clock and an output clock in response to the input clock and performs control to gradually suppress the detected phase difference to zero. The second PLL detects a phase difference between the input clock and an output clock in response to the input clock and performs control to suppress the detected phase difference to zero at a speed higher than that of the first PLL. The first phase difference detection unit detects a phase difference between the input clock and the output clock from the first PLL. The second phase difference detection unit detects a phase difference between the input clock and the output clock from the second PLL. The phase difference processing unit processes a detection of a difference between the phase differences detected by the first and second phase difference detection units. The frequency difference detection unit detects a frequency difference between the input clock and a reference frequency from a detection output from the phase difference processing unit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile