A 0.5 to 1.7 Gbps PI-CDR with a Wide Frequency-Tracking Range

Abstract

This paper proposes a continuous-rate clock-data-recovery (CDR) circuit that covers a data rate range of 500[Formula: see text]Mbps to 1.7[Formula: see text]Gbps. The proposed CDR is based on the phase interpolation principle and implemented in 130[Formula: see text]nm CMOS. The design utilizes digital voter and phase control logic instead of analog charge pump and filter, which facilitates migration among different technologies. To avoid the phase interpolator (PI) getting into the nonlinear region, multiple modes are selected to limit the frequency range of the sampling clock within 500[Formula: see text]MHz to 1[Formula: see text]GHz. A 5[Formula: see text]mm2 test chip is fabricated, where the CDR core occupies 0.359[Formula: see text]mm2 of silicon area. The PI achieves a resolution of 7 bits and a good linearity of 0.9955. The proposed CDR also achieves a BER less than 10[Formula: see text] and has a frequency tracking range of [Formula: see text][Formula: see text]ppm. The power consumed by the proposed CDR is 32.6[Formula: see text]mW/Gbps.