Signal sampling with sampling and reference paths

摘要

A signal-analyzing unit (10) comprises a sampling path (30) and a reference path (200) both receiving a digital test signal (20). The sampling path (30) comprises a first comparator (50) for comparing the test signal (20) against a first threshold value (Vth1) and providing a first comparison signal (50A) as result of the comparison, and a first sampling device (60) for receiving as input the first comparison signal (50A) together with a first timing signal (70) comprising a plurality of successive first timing marks, wherein the first sampling device (60) is adapted to derive a value of the first comparison signal (50A) for one or more of the first timing marks. The reference path comprises a second comparator (100) for comparing the test signal (20) against a second threshold value (Vth2) and providing a second comparison signal (100A) as result of the comparison, and a second sampling device (260) for receiving as input the second comparison signal (100A) together with a second timing signal (270) comprising a plurality of successive second timing marks, wherein the second sampling device (260) is adapted to derive a value of the second comparison signal (100A) for one or more of the second timing marks. An analysis unit (80) is provided for receiving and jointly analyzing the output of both of the sampling (30) and reference (200) path. <IMAGE>