| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a PLL synthesizer that can have statisfactory properties of fast actuation, low power consumption, and low spuriousness in a stationary state at the same time, and a lock detector which detects acquisition of synchronism. <P>SOLUTION: The PLL synthesizer which pulls in the frequency and phase of the output signal of a voltage-controlled oscillator with phase locked loop (PLL) constitution using a switching type variable frequency divider is equipped with the lock detector which monitors the control voltage Vvco of the voltage-controlled oscillator, decides whether its variation quantity ΔVvco is larger or smaller than a predetermined range, and outputs a synchronism decision signal when the variation quantity ΔVvco of the control voltage becomes smaller than the predetermined range. <P>COPYRIGHT: (C)2008,JPO&INPIT |
