| 摘要 |
PURPOSE:To correct a count error without using a clock of high repetitive frequency by dividing one period T of a clock equally by (m) and delaying a rectangular wave by T/m at every time. CONSTITUTION:A delay circuit 13 consists of m/2 delay circuits which divide one period T of the clock equally by (m) and delay the rectangular wave by T/m at every time. A detecting circuit 14 detects the difference between the leading edge of the output of an FF 12 operating with the rising rectangular wave and clock and the leading edge of the output of a phase detector 1 from the output of the delay circuit 13. A detecting circuit 15, on the other hand, detects the difference between the trailing edge of the output of the FF 12 and the trailing edge of the output of the phase detector 1 from the output of the delay circuit 13. Then, the phase difference found by a phase meter is N1+(N2-N3), where N1 is the output of an output terminal, N2 is the output of the detecting circuit 14, and N3 is the output of the detecting circuit 15. Consequently, a value which can not be corrected because of <=1 count of the counter 3 can be measured with the accuracy of the delay circuit 13.
|
