| 摘要 |
For prompt restoration of a PLL being in inactive state due to an abnormal oscillation of a voltage-controlled oscillator, it is checked that a frequen cy divider (4) provides a comparison signal (fc). If no comparison signal (fc) is detected, a phase comparator (1) is forced to decrease its output level temporarily to decrease the oscillating frequency of the voltage-controlled oscillator (3). The method is suitable for generation of a wide range of sampling clocks to be used for the digital processing of analog video signal s.
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