Patent Yard Sign in
Expired Canadian patentCanada

Digital-to-analog converter

CA 2039697 C · Owner: Fujitsu Limited · Inventors: Tokuhiro, Noriyuki

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

A digital-to-analog converter of a current addition type using weighted resistors includes an, input resistor network (4) for providing a resistance dependent on a digital input signal having a predetermined number of bits, and an adder (3) having a first input terminal coupled to the input resistor network and a second input terminal connectable to receive a reference potential, for adding a signal obtained at the first input terminal and the reference potential. The adder also has an output terminal via which a result of an adding operation is output and the, result of the adding operation shows an analog signal corresponding to the digital input signal. The digital-to-analog converter …

Read the whole patent

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 August 20, 1990 and granted April 15, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 20, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 20, 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.
FiledAugust 20, 1990
GrantedApril 15, 1997
Term endedAugust 20, 2010
Patent numberCA 2039697 C
Classification (IPC)H03M1/66 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedAug 20, 1990Patent grantedApril 15, 1997Term endedAug 20, 2010

Sources & verification

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