Pulse or digital communications – Repeaters – Testing
Patent
1997-02-13
1999-02-02
Chin, Stephen
Pulse or digital communications
Repeaters
Testing
375200, 375204, 375376, H04B 1500
Patent
active
058675248
ABSTRACT:
A clock circuit includes an oscillator for generating a reference frequency signal, and a spread spectrum clock generator cooperating with the oscillator for generating a spread spectrum clock output signal having a fundamental frequency and reduced amplitude EMI spectral components at harmonics of the fundamental frequency. The spread spectrum clock generator preferably includes a clock pulse generator for generating a series of clock pulses, and a spread spectrum modulator for frequency modulating the clock pulse generator to broaden and flatten amplitudes of EMI spectral components which would otherwise be produced by the clock pulse generator. The spread spectrum modulator frequency modulates the clock pulses with specific profiles of frequency deviation versus the period of the profile. Electronic devices including the spread spectrum clock circuit and associated method are also disclosed.
REFERENCES:
patent: 2352254 (1944-06-01), Curtis
patent: 2671896 (1954-12-01), DeRosa
patent: 2953780 (1960-04-01), Goldfischer
patent: 3354410 (1967-11-01), Beuscher
patent: 3388349 (1968-06-01), Ault
patent: 3764933 (1973-10-01), Fletcher et al.
patent: 3878527 (1975-04-01), Rensin et al.
patent: 3962653 (1976-06-01), Basset
patent: 4009450 (1977-02-01), Holcomb et al.
patent: 4507796 (1985-03-01), Stumfall
patent: 4578649 (1986-03-01), Shupe
patent: 4585997 (1986-04-01), Lin
patent: 4695808 (1987-09-01), Cabaniss et al.
patent: 4737968 (1988-04-01), Norton et al.
patent: 4943786 (1990-07-01), Cordwell et al.
patent: 4996684 (1991-02-01), Morley et al.
patent: 5028887 (1991-07-01), Gilmore
patent: 5036298 (1991-07-01), Bulzachelli
patent: 5095288 (1992-03-01), Dent
patent: 5144260 (1992-09-01), Stribling et al.
patent: 5148447 (1992-09-01), Ito
patent: 5216713 (1993-06-01), Lindholm
patent: 5249199 (1993-09-01), Mayer et al.
patent: 5263055 (1993-11-01), Cahill
patent: 5272454 (1993-12-01), Ikai et al.
patent: 5301367 (1994-04-01), Heinonen
patent: 5329253 (1994-07-01), Ichihara
patent: 5416434 (1995-05-01), Kootstra et al.
patent: 5488627 (1996-01-01), Hardin et al.
patent: 5491458 (1996-02-01), McCune, Jr. et al.
patent: 5659587 (1997-08-01), Knierim
EPO Search Report; Application No. EP 94 30 8802; 3/17/95.
Lin et al., Reduction of Power Supply EMI Emission by Switching Frequency Modulation, Virginia ower Electronics Center the VPEC Tenth Annual Power Electronics Seminar, pp. 129-136, Sep. 20-22, 1992.
Habetler et al., Acoustic Noise Reduction in Sinusoidal PWM Drives Using a Randomly Modulated Carrier, IEEE Transactions on Power Electronics, Vol. 6, No.s 3, Jul. 1991.
Tanaka et al., Random-Switching Control in DC-to-DC Converters, IEEE, pp. 500-507 (1989).
Commission Electrotechnique Internationale (Comite International Special Des Perturbations Radioelectriques, C.I.S.P.R. Specification for Radio Interference Measuring Apparatus and Measurement Methods, Publication 16, First Edition, 1977.
Booth James Ronald
Bush Donald Reid
Fessler John Thomas
Hardin Keith Bryan
Brady John A.
Chin Stephen
Lexmark International Inc.
Liu Shu-Wang
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