公开(公告)号：US5872807A

公开(公告)日：1999-02-16

申请号：US799914

申请日：1997-02-13

Applicant: James Ronald Booth ,  Donald Reid Bush ,  John Thomas Fessler ,  Keith Bryan Hardin

Inventor： James Ronald Booth ,  Donald Reid Bush ,  John Thomas Fessler ,  Keith Bryan Hardin

IPC: G06F15/78 ,  G06F1/04 ,  H03B29/00 ,  H03C3/09 ,  H03K4/94 ,  H03L7/07 ,  H03L7/08 ,  H03L7/087 ,  H03L7/18 ,  H03L7/197 ,  H04J13/00 ,  H04B15/00

CPC classification number: H03C3/0966 ,  H03B29/00 ,  H03C3/0925 ,  H03C3/0941 ,  H03L7/07 ,  H03L7/0805 ,  H03L7/087 ,  H03L7/18 ,  H03L7/197 ,  H04B2215/064 ,  H04B2215/067

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.

公开(公告)号：US5867524A

公开(公告)日：1999-02-02

申请号：US800890

申请日：1997-02-13

Applicant: James Ronald Booth ,  Donald Reid Bush ,  John Thomas Fessler ,  Keith Bryan Hardin

Inventor： James Ronald Booth ,  Donald Reid Bush ,  John Thomas Fessler ,  Keith Bryan Hardin

IPC: G06F15/78 ,  G06F1/04 ,  H03B29/00 ,  H03C3/09 ,  H03K4/94 ,  H03L7/197 ,  H04B15/00

CPC classification number: H03C3/0966 ,  H03B29/00 ,  H03C3/0925 ,  H03C3/0941 ,  H03L7/0805 ,  H03L7/197 ,  H04B2215/064 ,  H04B2215/067

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.

Abstract translation: 时钟电路包括用于产生参考频率信号的振荡器和与振荡器协作的扩展频谱时钟发生器，用于产生具有在基频的谐波处的基频和降低幅度的EMI频谱分量的扩频时钟输出信号。 扩频时钟发生器优选地包括用于产生一系列时钟脉冲的时钟脉冲发生器和用于对时钟脉冲发生器进行频率调制的扩展频谱调制器，以扩大和平缓由EMI时钟脉冲发生器产生的EMI频谱分量的幅度 。 扩频调制器利用频率偏差的特性曲线与轮廓周期调制时钟脉冲。 还公开了包括扩频时钟电路和相关方法的电子设备。