On the jitter requirements of the sampling clock for analog-to-digital converters

N. Da Dalt1, M. Harteneck2, C. Sandner1, A. Wiesbauer3
1Mixed Signal Department,Development Centers Austria, Infineon Technologies AG, Villach, Austria
2COM A2, Infineon Technologies AG, Munich, Germany
3COM MS 1 Development Centers Austria, Infineon Technologies AG, Villach, Austria

Tóm tắt

In this work, the effect of sampling clock jitter on the SNR of an analog-to-digital (AD) conversion is investigated from a practical perspective. Aperture jitter analyses have been dealing up to now with white spectrum jitter. This assumption does not hold for the output of phase-locked loops (PLL)-like frequency synthesizers, where the spectrum is shaped by the loop transfer function. Based on a linear approximation, a powerful expression for the SNR is derived, applicable to a jitter process with a generic autocorrelation function and generic input signal. A lot of different definitions of jitter are available in the literature; this work addresses also the problem of identifying correctly among them the "effective" jitter for a given SNR. This can be profitably used in the specification as well as verification of the jitter requirements of a frequency synthesizer used as sampling clock generator in the AD converter systems. The results have been checked through numerical simulation.

Từ khóa

#Jitter #Sampling methods #Clocks #Analog-digital conversion #Frequency synthesizers #Apertures #Phase locked loops #Transfer functions #Linear approximation #Autocorrelation

Tài liệu tham khảo

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