Pulse or digital communications – Synchronizers – Phase displacement – slip or jitter correction
Reexamination Certificate
2008-07-08
2008-07-08
Bocure, Tesfaldet (Department: 2611)
Pulse or digital communications
Synchronizers
Phase displacement, slip or jitter correction
C375S147000
Reexamination Certificate
active
07397883
ABSTRACT:
The present invention provides a spread spectrum type clock generation circuit whose EMI for peripheral equipment is reduced. The clock generation circuit comprises a phase-locked loop circuit and a clock modulation circuit. The clock modulation circuit comprises a ΔΣ modulator, to frequency-modulate an output clock by modulating the frequency division number of a frequency divider in the phase-locked loop circuit by a digital circuit, and further comprises a modulation pattern controller for distributing the peak of a triangular waveform which is a modulation waveform generated by a modulation pattern generator to change the amplitude and the period thereof, thereby making it possible to eliminate dullness and distortion of a modulation waveform in a modulating method using a conventional analog circuit and to obtain an output clock having higher modulation efficiency than that in a case where a normal triangular waveform is employed in a conventional modulating method using a digital circuit.
REFERENCES:
patent: 5488627 (1996-01-01), Hardin et al.
patent: 5631920 (1997-05-01), Hardin
patent: 6404834 (2002-06-01), Hardin et al.
patent: 6504498 (2003-01-01), O'Brien
patent: 6559698 (2003-05-01), Miyabe
patent: 6697416 (2004-02-01), Jennings
patent: 6943598 (2005-09-01), Ghazali et al.
patent: 6975687 (2005-12-01), Jackson et al.
patent: 2002/0022465 (2002-02-01), McCullagh et al.
patent: 9-098152 (1997-04-01), None
patent: 2001-117662 (2001-04-01), None
Kim et al., “Spread Spectrum Clock generator with Delay Cell Array to Reduce Electromagnetic Interference,” 2005, IEEE, pp. 908-920.
Kim et al., “Spread Spectrum Clock generator with Delay Cell Array to Reduce EMI from a High-Speed Digital System,” 2004, IEEE, pp. 820-825.
Kao et al., “A Wide Input-Range ΣΔ Modulator for Application to Spread-Spectrum Clock generator,” 2006, IEEE, pp. 830-833.
Bocure Tesfaldet
Jordan and Hamburg LLP
Seiko NPC Corporation
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