| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase-locked oscillator that can accurately determine a locked state and an unlocked state in comparison with conventional ones. <P>SOLUTION: A phase-locked oscillator includes a sampling phase detector SPD. The sampling phase detector SPD outputs a voltage signal in accordance with a phase difference between a reference signal and an oscillation signal output form a voltage-controlled oscillator VCO. A Schmitt circuit 34 generates a pulse signal in accordance with an output of the sampling phase detector. A determination circuit determines locking/unlocking in accordance with the presence or absence of a pulse signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
