| 摘要 |
PURPOSE:To prevent the malfunction due to the asynchronism between an input data and the clock, by latching the input data synchronously with the clock given from a voltage control oscillator and obtaining a one-shot pulse from the latch output to supply it to a phase comparator. CONSTITUTION:An input data signal 20 is applied to a D type FF5 and latched synchronously with the clock signal given from a voltage control oscillator 4. The output 28 of the FF5 is supplied to a one-shot circuit consisting of D type FF11 and 12, an EX-OR13 plus an AND14. Thus an output pulse 25 equivalent to a clock is obtained in accordance with the rise of an input data. A wind controller 2 counts the clocks to produce a dummy data signal 26. The signal 26 and the pulse 25 are applied to a phase comparator 3. The comparator 3 applies the control output voltage 27 corresponding to the phase error between the signal 26 and the pulse 25 to the oscillator 4. |
