Half baud-rate, low BER PAM-4 CDR based on SS-MMSE algorithm
A hardware-efficient four-level pulse amplitude modulation (PAM-4) clock and data recovery (CDR) circuit for high speed serial links is proposed, following a sign-sign minimum mean square error (SS-MMSE) algorithm. Using a specially designed continuous-sampling slope detector and a dual-stage digital filter, the proposed SS-MMSE CDR can align the clock phase well with the maximum vertical eye opening, as opposed to the conventional Bang-Bang CDR which only finds the midpoint of a symbol, yet requiring extra clock phases or running at higher frequency. Simulation results confirm superior performance and implementation efficiency of this proposed SS-MMSE PAM-4 CDR over the Bang-Bang design. © The Institution of Engineering and Technology 2016.
Half baud-rate, low BER PAM-4 CDR based on SS-MMSE algorithm.
Electronics Letters, 52(25),