Control of Clock Jitter in High Speed Data Links
نویسنده
چکیده
Fast data links require a low phase noise reference clock. An alternative is to reduce the noise of a low cost clock part using the band pass filtering inherent to the clocking architecture in the link. This study has a two-fold objective: to verify clock noise filtering in a 16 Gbps data link, and to prove the degree of filtering is adjustable. Two measured band pass filters are presented. Clock jitter reduction can be achieved by narrowing the difference in the loop bandwidths of the Tx PLL and Rx PLL, and by setting the band pass filter at the noise floor of the reference clock. Therefore, 16 Gbps data links can be designed to filter the reference timing signal, eliminating the need for a clean, expensive clock source.
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