| 摘要 |
PROBLEM TO BE SOLVED: To stabilize a phase difference of an oscillated signal with respect to a reference signal in a PLL circuit and to render its phase difference and a loop band variable. SOLUTION: The oscillating apparatus is provided which includes: a filter circuit including a capacitor and outputting a control signal on the basis of an electric charge amount stored in the capacitor; an oscillator for outputting an oscillated signal with a frequency determined on the basis of the control signal; a phase comparator for detecting a phase difference between the oscillated signal and the reference signal by comparing the oscillated signal with the reference signal having a predetermined frequency; a switch circuit for controlling whether the capacitor is charged by a prescribed charging current or discharging the capacitor at a prescribed discharge current on the basis of the phase difference; and a current stabilizing circuit for determining each of the charging current and the discharge current on the basis of a predetermined reference current or reference voltage. COPYRIGHT: (C)2007,JPO&INPIT
|
