A 2 Gbps to 12 Gbps Wide-Range CDR with Automatic Frequency Band Selector

摘要

The need for wide-band clock and data recovery（CDR） circuits is discussed.A 2 Gbps to 12 Gbps continuous-rate CDR circuit employing a multi-mode voltage-control oscillator（VCO）,a frequency detector,and a phase detector（FD＆PD） is described.A new automatic frequency band selection（FBS） without external reference clock is proposed to select the appropriate mode and also solve the instability problem when the circuit is powering on.The multi-mode VCO and FD/PD circuits which can operate at full-rate and half-rate modes facilitate CDR with six operation modes.The proposed CDR structure has been modeled with MATLAB and the simulated results validate its feasibility.