| 摘要 |
PURPOSE:To unnecessitate a hysteresis circuit at a comparator part, and to effectively remove noise or jitter components without sacrificing a frequency characteristic by removing the noise or jitter from a digital signal. CONSTITUTION:D type FF circuits 12 and 14, and EX-OR circuits 16 and 18 respectively constitute differentiation circuits, and the rising of differential signals Sa3 and Sb3 searched from digital signals Sa1 and Sb1 whose phases are different respectively indicate the change of the Sa1 and Sb1. The digital signal Sa1 and the differential signal Sb3 are inputted to a D type FF circuit 20, and the Sa1 established by the rising of the Sb3 is outputted as a noise removing signal Sa1'. That is, the Sa1' is not changed even when the Sa1 is changed as long as the Sb1 is not changed, and even when the noise or jitter components are present in the Sa1, they can be prevented from being appearing in the Sa1'. In the same way, a noise removing signal Sb1' can be obtained from the Sb1. Thus, the noise or jitter can be removed by the satisfactory frequency characteristic. |
