Frequency doubler with a variable delay circuit and exclusive or gate
CA 2067562 C · Owner: Nec Corporation · Inventors: Tatsumi, Satoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A doubling circuit for adjusting the duty ratio of an output signal automatically and implemented as a digital circuit. A variable delay circuit delays an input signal while an exclusive-OR (EOR) gate produces EOR of the output signal of the delay circuit and the input signal. The resulting output of the EOR gate has a frequency double the frequency of the input signal. A low pass filter (LPF) filters the output signal of the EOR gate to produce a mean voltage thereof. An integrating circuit integrates a difference between the output voltage of the LPF and a reference voltage. The delay of the variable delay circuit is controlled by the output of the integrating circuit. As a result, the …
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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 April 29, 1992 and granted April 22, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2014.
- 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.