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Expired Canadian patentCanada

Charge pump circuit

CA 2019778 C · Owner: Takagi, Kotaro · Inventors: Yokoya, Satoshi; Takagi, Kotaro

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

A charge pump circuit for charging a capacitor in response to a phase difference between first and second input signals comprises a constant current source for providing a first constant current; a constant current sink for absorbing a second constant current; a circuit for substantially equalizing the magnitudes of the first and second constant currents; and a switching circuit for providing the first constant current and the second constant current flowing in opposed directions to the capacitor through an output terminal of the charge pump circuit in response to the phase difference between the first and second input signals to produce a voltage level across the capacitor corresponding to …

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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

  • Filed June 26, 1990 and granted November 30, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 26, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 26, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 26, 1990
GrantedNovember 30, 1999
Term endedJune 26, 2010
Patent numberCA 2019778 C
Classification (IPC)H03L7/08 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 26, 1990Patent grantedNov 30, 1999Term endedJune 26, 2010

Sources & verification

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