A Half-Rate Bang-Bang Phase/Frequency Detector for Continuous-Rate CDR Circuits

A half-rate bang-bang phase and frequency detector (BBPFD) is presented for continuous-rate clock and data recovery (CDR) circuits. The proposed half-rate BBPFD not only preserves the advantages of conventional BBPDs, but also has the infinite unilateral frequency detection range. To verify the proposed circuit, a continuous-rate CDR circuit with the proposed BBPFD has been fabricated in a 0.18um CMOS process. It can recover the NRZ data with the bit rate ranging from 622 Mbps to 3.125 Gbps. The measured bit-error rate is less than 10^-12. The core area is 0.33 x 0.27 mm² and the power consumption is 80 mW from a 1.8 V supply.