A Baud-Rate Clock and Data Recovery With Collaborative Maximum-Eye Tracking Method

Abstract

Baud-rate CDRs are preferred over 2x-oversampling CDRs in energy-efficient receivers. However, conventional baud-rate CDRs using sign-sign Mueller-Muller phase detectors suffer from sub-optimal timing locking point. Therefore, to overcome this issue, a maximum-eye tracking (MET) method that tracks optimal lock point has been introduced. This paper applies MET to multi-lane baud-rate CDR design. Comparing biased data levels of 4 lanes, it sets proper timing update ratio. As a result, the CDR has a lock point with maximum-eye height by collaborative MET algorithm. Also, it can reduce power consumption in multi-phase clocking. In comparison with prior art, it searches the optimal lock point more efficiently and fast.