| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce influence of flicker noise and reduce offset frequency dependence of noise density of an output from a charge pump circuit even when a phase comparison frequency is high. Ž<P>SOLUTION: In a charge pump circuit provided in a PLL circuit to control on/off of a current source for discharging a current and a current source for absorbing a current depending on a control signal outputted from a phase comparison circuit, an electric charge storing/discharging circuit that stores electric charge from the current source depending on a storing period signal and outputs the stored electric charge depending on an output period signal is provided. The storing period signal is set to have a period that strides over a plurality of cycles of the control signal from the phase comparison circuit. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
