| 摘要 |
PROBLEM TO BE SOLVED: To reduce a leak current that flows to a charge pump circuit while charge pump operation is stopped.SOLUTION: A PLL circuit includes a plurality of charge pump circuits each for generating a charge pump current at a common output node connected to a low-pass filter. The charge pump circuit includes: a first current source as a constant current source of a discharge type to the output node; a first switch for switching a connection of the first current source and the output node; a second current source as a constant current source of a suction type to the output node; and a second switch for switching a connection of the second current source and the output node. At least one of the charge pump circuits includes potential equalization means for regulating a first node between the first current source and the first switch, a second node between the second current source and the second switch, and the output node to an equal potential while the charge pump circuit stops the charge pump operation.SELECTED DRAWING: Figure 2 |
