Sampling Error Estimation in High-Speed Sampling Systems Introduced by the Presence of Phase Noise in the Sampling Clock

Salam Marougi
Agilent Technologies


The presence of phase noise in the sampling clock of fast Analog-to-Digital converters introduces time jitter into the sampling instants of the Analog-to-Digital converter. In this paper, an analysis has been performed to quantify the impact of phase perturbation in the sampling clock on the signal-to-noise ratio of the digitized waveform. Close form formulae have been obtained for the signal-to-jitter noise (S/Njit) ratio when the phase perturbation is random as well as when it is dominated by a periodic and deterministic component. The result obtained is then used to predict the jitter noise generated by a sampling clock with typical phase noise performance. The results obtained will help identify the impact of the various sampling and phase noise parameters on the resulting S/Njit ratio.