PI-based CDR

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PI-based vs. PLL-based CDR

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PCI Express Jitter Modeling Revision 1.0RD July 14, 2004

Phase Interpolator (PI)

!!! Clock Edges

And for a phase interpolator, you need those reference clocks to be completely the opposite. Ideally they would be triangular shaped

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four input clocks given by the cyan, black, magenta, red

John T. Stonick, ISSCC 2011 tutorial. "DPLL Based Clock and Data Recovery" [https://www.nishanchettri.com/isscc-slides/2011%20ISSCC/TUTORIALS/ISSCC2011Visuals-T5.pdf]

kink problem

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B. Razavi, "The Design of a Phase Interpolator [The Analog Mind]," IEEE Solid-State Circuits Magazine, Volume. 15, Issue. 4, pp. 6-10, Fall 2023.(https://www.seas.ucla.edu/brweb/papers/Journals/BR_SSCM_4_2023.pdf)