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:
Dec. 25, 1990
Filed:
May. 26, 1989
Applicant:
Inventors:
Assignee:
Siemens AG, , DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
375108 ; 331 18 ; 375120 ;
Abstract
A method and apparatus for synchronization of a clock generator, especially a clock generator of a digital telecommunications exchange. When there is a brief outage of the reference frequency, the voltage controlled oscillator of the phase control circuit whose output frequency determines the frequency of the clock generator continues to operate with the control voltage prevailing until then. Upon resumption of the reference frequency, the phase difference between the reference frequency and the output frequency of the oscillator is measured and corrected with the value of the valid phase difference before the loss of the reference frequency. The corrected value is used as the basis for resumed frequency control.