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Title:
METHOD FOR RESTRICTING RADIATION OF ELECTROMAGNETIC INTERFERENCE NOISE IN DIGITAL SYSTEM AND ITS DEVICE
Document Type and Number:
Japanese Patent JP3631573
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To digitally reduce an electromagnetic interference noise level by obtaining a first signal from a base signal by means of a digital system so as to execute modulation, obtaining a modulation reference signal which is fluctuated between an upper limit and a lower limit so as to generate a clock signal and diffusing the radiation of the electromagnetic interference noise of the clock signal.
SOLUTION: Shortest transition corresponding to the base signal 13 is adopted as the active transition of the first signal 20 having a desired average frequency so that the first signal 20 is guided from the base signal 13 by the digital system. Then, modulation is executed in the frequency of the first signal 20 and the modulation reference signal 16 having the frequency which periodically fluctuates between the upper limit and the lower limit is obtained. Moreover, the clock signal is generated from the modulation reference signal 16. Then, the radiation of the electromagnetic interference noise of the modulation reference signal 16 is diffused over a first frequency band and the radiation of the electromagnetic interference noise of the clock signal is diffused over the second frequency band. Thus, the radiation of electromagnetic interference noise in the digital system is restricted.


Inventors:
Robert bee packet
Preston Dee Brown
Application Number:
JP34982096A
Publication Date:
March 23, 2005
Filing Date:
December 27, 1996
Export Citation:
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Assignee:
HEWLETT-PACKARD COMPANY
International Classes:
H04L25/02; G06F1/04; G06F1/10; G06F7/62; H03K5/156; H03K7/00; H03K23/66; H03L7/06; H04B1/68; G09G5/18; (IPC1-7): H04L25/02; H04B1/68
Domestic Patent References:
JP6244721A
JP61024321A
JP9232944A
Foreign References:
US5426392
US4023116
US4933890
Attorney, Agent or Firm:
Satoshi Furuya
Kaoru Furuya
Takahiko Mizobe