A 5-Gbit/s CDR circuit with 1.4 mW multi-PFD phase rotating PLL

With a new phase-rotating phase locked loop (RPLL), a 5-Gbit/s quarter-rate clock and data recovery (CDR) circuit is presented in this brief. The RPLL employs a split-tuned architecture to decouple the tradeoff between RPLL bandwidth and power consumption. The uncertainty of phase interpolation due to the non-deterministic characteristics of the phase frequency detector (PFD) is eliminated by employing a PFD synchronizer (PFDS). Hence RPLL precisely performs seamless phase adjustment. The CDR, implemented in a digital 65 nm CMOS technology, shows 5.5-ps rms and 47.2-ps peak-to-peak jitter in the recovered clock and 10−12 bit error rate while consuming 10.3mW from a 1.2-V supply.