A 5-Gb/s 2.67-mW/Gb/s Digital Clock and Data Recovery With Hybrid Dithering Using a Time-Dithered Delta-Sigma Modulator

Abstract

A digital clock and data recovery (CDR) employing a time-dithered delta-sigma modulator (TDDSM) is presented. By enabling hybrid dithering of a sampling period as well as an output bit of the TDDSM, the proposed CDR enhances the resolution of digitally controlled oscillator, removes a low-pass filter in the integral path, and reduces jitter generation. Fabricated in a 65-nm CMOS process, the proposed CDR operates at 5-Gb/s data rate with BER < 10(-12) for PRBS 31. The CDR consumes 13.32 mW at 5 Gb/s and achieves 2.14 and 29.7 ps of a long-term rms and peak-to-peak jitter, respectively.