New Multilevel Bang-Bang Phase Detector

Equivalent time oscilloscopes are widely used as an alternative to real-time oscilloscopes when high timing resolution is needed. For their correct operation, they need the trigger signal to be accurately aligned to the incoming data, which is achieved by the use of a clock and data recovery circuit (CDR). In this paper, a new multilevel bang-bang phase detector (BBPD) for CDRs is presented; the proposed phase detection scheme disregards samples taken close to the data transitions for the calculation of the phase difference between the inputs, thus eliminating metastability, one of the main issues hindering the performance of BBPDs.