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. 29, 1980
Filed:
Dec. 22, 1978
Applicant:
Inventors:
Charles E Mendenhall, Campbell, CA (US);
Randall L Sandusky, San Jose, CA (US);
Assignee:
Sperry Rand Corporation, New York, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
H03B / ; H03K / ; H03K / ;
U.S. Cl.
CPC ...
331 / ; 307232 ; 328133 ; 328155 ; 331 11 ; 331 14 ; 331 27 ;
Abstract
A phase comparator for a digital phase locked loop which provides first and second order error signals for phase and frequency correction of a voltage controlled oscillator in the loop with respect to data being read for self synchronization of the data. A first order error signal is generated in a first phase detector which operates only during a VCO 'unsafe' condition, i.e., when a data pulse is beyond a present limit. A finer, second order error signal is generated in a second phase detector which operates only during a VCO 'safe' condition, i.e., when a data pulse is within a preset limit.