A Wide-Range FD for Referenceless Baud-Rate CDR Circuits

A wide-range frequency detector (FD) is presented for baud-rate clock and data recovery (CDR) circuits. It achieves a wide frequency capture range, a short lock time, and a low power. By using this FD, a referenceless quarter-rate CDR circuit with a one-tap decision feedback equalizer is fabricated in 40-nm CMOS technology. The active area of this CDR circuit is 0.0999mm
²
and its power is 44mW while the data rate is 16.8Gbps. The calculated energy efficiency of this CDR circuit is 2.62pJ/b.