| 摘要 |
PURPOSE:To expand the operation range by making it possible to obtain the phase comparison output even in the period of pulse width of the reset pulse in the phase comparator circuit for which the FF is used. CONSTITUTION:The input clock which has been provided to the terminal 11 is applied to the reset terminal R of the FF13 after its rise has been detected by the rise detecting circuit 12. Also, the output clock which has been provided to the terminal 22 is applied to the clock terminal C of the FF13, a signal of pulse width corresponding to the phase difference of the input/output clocks is output from the terminal Q', and it is applied to the switching circuit 20. Moreover, the input/ output clocks are applied to the exclusive ''or'' circuit 14 and the logical product circuit 15, and the outputs are also applied to the switching circuit 20. On the other hand, the FF19 is set and reset in case when the output clock is ''1'' and ''0'', respectively, when there is an output of the rise detecting circuit 12. And, the switching circuit 20 selects an output of the logical product circut 15 and an output of the FF13, in case when the output of the FF19 is ''1'', and ''0'', respectively. |
