10-Gb/s Inductorless CDRs With Digital Frequency Calibration

Two 10-Gb/s inductorless clock and data recovery (CDR) circuits using different gated digital-controlled oscillators (GDCO) are presented. A digital frequency calibration is adopted to save the power consumption and chip area. They have been fabricated in 0.18-mum CMOS process. By using the complementary gating technique, the first CDR circuit occupies an active area of 0.16 mm² and draws 36 mW from a 1.8 V supply. The measured rms jitter and peak-to-peak jitter is 8.5 ps and 42.7 ps , respectively. By using the quadrature gating technique, the second CDR circuit consumes an active area of 0.25 mm² and its power consumption of 56 mW. The measured rms jitter and peak-to-peak jitter is 3.4 ps and 21.8 ps, respectively. The power of the second CDR circuit is higher than that of the first one but its jitter is reduced.