| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spread spectrum clock generator that is capable of preventing phase jumps and jitters and suppressing the spurious radiation components and that can easily be applied to large scale integrated circuits. <P>SOLUTION: The spread spectrum clock generator can be configured with a filter 7, a bit thinning circuit 8 and a fractional divider 51. In the circuit configuration, by combining a ΔΣ quantizer and the fractional divider so that sine wave modulation and random number modulation can be realized, control with digital values can be performed. This clock generator prevents the occurrence of a sharp phase change in an output high frequency clock fo and makes fine phase controlling possible. Consequently, EMI reduction of 20-30 dB can be expected. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
