| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spectrum spreading clock generator capable of high-accuracy frequency modulation. <P>SOLUTION: In the spectrum spreading clock generator, a PLL circuit 31 outputs clock signals CLKV1 to CLKV5 whose phases are respectively different. A selector 23 selects one from among the clock signals CLKV1 to CLKV5, while a control circuit 24 controls the signal selection operation of the selector 23. An input frequency demultiplier 1 outputs a reference clock signal CLKR, by carrying out frequency demultiplication of the selected clock signal. A PLL circuit 21 generates an oscillation clock signal CLKO, by carrying out frequency multiplication of the reference clock signal CLKR, and thereby, the phase of the oscillation clock signal CLKO can be adjusted finely. As a consequence, a spread spectrum clock generator capable of high-accuracy frequency modulation can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT |
