| 摘要 |
PROBLEM TO BE SOLVED: To provide a charge pump circuit which constitutes a PLL circuit etc. is capable of making its output current stable, and effectively restraining jitters from occurring in its oscillation output signals; and to provide the PLL circuit etc. using the same. SOLUTION: The charge pump circuit is equipped with a first and a second constant current source, furthermore a first switch which is turned ON to output a current from the first constant current source to the output side of the charge pump circuit when up-signals are at a high level, a second switch which is turned ON to enable a current from the first constant current source to flow through a node having a middle potential between a first and a second power source when up-signals are at a low level, a third switch which is turned ON to make a current flow from the output side of the circuit to the second constant current source when down-signals are at a high level, and a fourth switch which is turned ON to make a current flow from the node having a middle potential between the first and second power sources to the second constant current source when down-signals are at a low level. COPYRIGHT: (C)2008,JPO&INPIT
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