| 摘要 |
PURPOSE:To realize the measurement of the delayed time with high accuracy and an easy operation, by counting the period of an output signal at the time when the input and output signals of a circuit part to be measured are equal in phase and then measuring the frequency or the period. CONSTITUTION:The output frequency signal sent from a voltage control oscillator 1 is supplied to a circuit part 7 to be measured. Thus the phases of frequencies f1 and f2 are equal to each other for the two input signals of a phase comparator 2. Furthermore the line lengths l1 and l2 from points A and B through the comparator 2 are set equal or shortest. As a result, the points A and B are set equal in phase. In other words, the oscillator 1 oscillates with period equal to the delayed time between the points A and B. Then the frequency or the period is measurd for the output signal at the point B by a counter 6 which is connected to the point B. In such way, the delayed time of the circuit part 7 can be easily measured with high accuracy. |
