| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase locked loop circuit and a semiconductor integrated circuit of low power consumption capable of accurately determining an operation state. <P>SOLUTION: An operation state determination part 6 determines whether or not a PLL frequency synthesizer is in a desired operation state based on whether or not a control voltage outputted from a loop filter 3 is within a prescribed voltage range. A current control circuit 51 executes control so as to reduce the drive current of a feedback frequency divider circuit 5 within the range that the PLL frequency synthesizer maintains the desired operation state on the basis of determination signals from a determination circuit 13. Thus, the operation state of the PLL frequency synthesizer is accurately determined. Also, it becomes possible to detect the malfunction of the feedback frequency divider circuit 5 as well. Further, by providing the current control circuit 51, the power consumption of the PLL frequency synthesizer is lowered. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
