Title:
拡大スペクトル・クロック生成器及び関連方法
Document Type and Number:
Japanese Patent JP3997248
Kind Code:
B2
Abstract:
A clock circuit includes an oscillator (15) for generating a reference frequency signal, and a spread spectrum clock generator (14) 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.
Inventors:
Case Be Hardin
John Tea Fesler
Donald Earl Bush
James Earl Booth
John Tea Fesler
Donald Earl Bush
James Earl Booth
Application Number:
JP2006063644A
Publication Date:
October 24, 2007
Filing Date:
March 09, 2006
Export Citation:
Assignee:
LEXMARK INTERNATIONAL,INC
International Classes:
G06F15/78; H03K7/06; G06F1/04; H03B29/00; H03C3/09; H03K4/94; H03L7/197
Domestic Patent References:
| JP27734A | ||||
| JP475469U |
Attorney, Agent or Firm:
Kunihiko Ohashi