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:
Feb. 28, 1978
Filed:
Feb. 22, 1977
Applicant:
Inventors:
David E Sanders, St. Petersburg, FL (US);
Ramon P Chambers, Clearwater, FL (US);
Robert S Gordy, Largo, FL (US);
Assignee:
NCR Corporation, Dayton, OH (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H03B / ; H03D / ;
U.S. Cl.
CPC ...
331-4 ; 329122 ; 331 19 ; 331 23 ; 331 25 ;
Abstract
Apparatus and method are provided to discriminate between true locking of a phase-locked loop on the main lobe of an information signal, and false locking on a side lobe thereof. The energy in the locked signal is sensed and compared with the signal energy at fixed frequency increments, preferably twice the bit clock rate frequency, above and below the lock frequency. A greater energy content at the increment frequencies than at the locked frequency indicates a false lock condition and is used to inhibit the loop from entering a locked mode.