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:
Jun. 29, 2004
Filed:
Jun. 29, 1998
Applicant:
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H04L 7/06 ;
U.S. Cl.
CPC ...
H04L 7/06 ;
Abstract
A PLL frequency synthesizer including a lock detection circuit which detects whether or not the PLL is locked. First and second phase difference signals are generated from a reference signal and a compared signal by a phase comparator. The lock detection circuit determines the locked condition and generates a clock detection signal using only the first and second phase difference signals and does not require an external clock signal. The lock detection signal is generated independently of the frequencies of the reference signal and the compared signal.