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:
Apr. 20, 1999
Filed:
Sep. 22, 1997
Applicant:
Inventor:
Christopher Huw Williams, Chepstow, GB;
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L / ;
U.S. Cl.
CPC ...
331 17 ; 331 25 ; 331D / ; 360 51 ; 375376 ;
Abstract
A phase lock loop for recovering a bit clock from a signal containing variations in the bit rate includes mans for resetting the frequency of said phase lock loop to a preset value if the loop loses its lock or if adverse conditions are detected. The loop may be reset if the frequency passes a preset limit or if other apparatus responsive to signal quality or signal to noise ratio detects adverse conditions. In one embodiment the signal is also subjected to automatic gain control and to adaptive filtering, and the frequency may be reset if the A.G.C. and/or the adaptive filter coefficients pass preset thresholds.