| 摘要 |
PURPOSE:To reduce the transient time during which an asynchronous state is changed to a synchronous state of phase, by adding an asynchronism detecting circuit and a phase controlling circuit to a phase synchronous oscillating circuit and monitoring the relative relation between an output signal and an input signal. CONSTITUTION:A phase comparator 101 compares an input signal 1 with the phase of an output 5 of an 1/N dividing circuit 104. This output 2 is supplied to a voltage control oscillating circuit 103 via a low-pass filter circuit 102. The output 4 of the circuit 103 is divided by the circuit 104, and the output 5 is fed back to the circuit 101. On the other hand, the output 5 is applied also to an asynchronism detecting circuit 105, and an alarm signal 6 is produced when the phase is asynchronous between the signals 1 and 5 to open a gate circuit 106. The output of the circuit 106 is delayed and supplied to a gate controlling circuit 108 along with the circuits 101 and 104. The output of the circuit 108 is fed back to the circuit 106. |
