A low-jitter BMCDR for half-rate PON systems

Abstract

This letter presents a 2.5 Gb/s half-rate burst-mode clock and data recovery (BMCDR) with enhanced jitter performance. Compared to conventional half-rate BMCDRs, the proposed work uses a single loop gated voltage controlled oscillator (GVCO) to minimize the timing mismatch. And the GVCO has only one gated delay cell to improve jitter performances. In addition, a tri-state phase detector for digital frequency calibration is also proposed in this letter to further reduce jitter caused by the frequency offset between the input data and the GVCO free running clock. The fabricated chip in a 110nm CMOS technology occupies the area of 0.08 mm². The proposed BMCDR consumes 29 mW with the measured peak to peak jitter of 17.8 ps_p−p (0.022 UI_p−p).