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Expired Canadian patentCanada

Dual-tracking phase-locked loop

CA 1304793 C · Owner: Devries, Paul Arthur · Inventors: Devries, Paul Arthur

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A dual-tracking phase-locked loop circuit is provided for moving with minimum disruption from conventional PLL operation to processor-controlled tracking of another closely related clock. In addition to conventional PLL components the circuit comprises a processor-controlled up/down counter which may operate alternatively as a link in the loop or as providing the base-line frequency determining value at the time of transition from PLL to processor-controlled tracking operation, thereby ensuring none disruptive transition.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted July 7, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 7, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 10, 1988
GrantedJuly 7, 1992
Term endedJuly 7, 2009
Patent numberCA 1304793 C
Classification (IPC)H03L7/08 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedMay 10, 1988Patent grantedJuly 7, 1992Term endedJuly 7, 2009

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.