Patent · US Expired

Method and apparatus for transparently switching clock sources

US5059925A · kind A · utility

99Cited by
4References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 28, 1990
Grant dateOct 22, 1991
Priority date
Expiry dateSep 28, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04J3/0688
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus for stably maintaining an output clock signal from a phase-locked loop (PLL) frequency multiplier when switching from one clock source to another clock source is described. This method and apparatus maintains the phase relationship between the external signal to the phase detector and the feedback signal from the divider to the phase detector.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.