Subscriber line interface circuit
CA 1260170 A · Owner: Fujitsu Limited · Inventors: Iketani, Yozo; Ayano, Mitsutoshi; Shibuya, Kiyoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A balanced type subscriber line interface circuit capable of being fabricated at least partly in a monolithic IC is described. The battery feed circuit comprises three pairs of mirror circuits connected to each other so as to eliminate longitudinal noise and noise induced in the voltage source. Overcurrent protection is achieved by varying the mirror ratio of current feeding mirror circuits when the subscriber line current exceeds a threshold value. A 2- to 4-wire converter has its frequency characteristics compensated by feeding back a current with an impedance network composed of two impedance elements each having respectively an impedance N time as high as that of the load impedance and …
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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 September 26, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 26, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.