| 摘要 |
PROBLEM TO BE SOLVED: To widen the frequency band of jitter, which can be measured, without adjusting it without using a special device by extracting a clock component from an input signal, distributing a clock, comparing the phase of the clock with that of a clock where a jitter component contained in the clock is suppressed and inputting the output signal level of a phase comparison result. SOLUTION: BPF 23 extracts the clock component of a frequency similar to a signal and a distributor 24 distributes the clock component into two. PLL 25 outputs the clock component of a waveform where the jitter component is suppressed. A mixer 26 compares the phases of the clock components from the distributor 24 and PLL 25. A capacitor 27 removes a DC component from the output signal of the mixer 26 and a peak detector 28 detects a peak. LPF 29 executes integration. The output of LPF 29 is inputted to a comparator 30, it is compared with proper reference voltage Vref and therefore the jitter component can be estimated.
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