A Fast Locking All-Digital Phase-Locked Loop via Feed-Forward Compensation Technique

Abstract

A fast locking all-digital phase-locked loop (ADPLL) via feed-forward compensation technique is proposed in this paper. The implemented ADPLL has two operation modes which are frequency acquisition mode and phase acquisition mode. In frequency acquisition mode, the ADPLL achieves a fast frequency locking via the proposed feed-forward compensation algorithm. In phase acquisition mode, the ADPLL achieves a finer phase locking. To verify the proposed algorithm and architecture, the ADPLL design is implemented by SMIC 0.18-μm 1P6M CMOS technology. The core size of the ADPLL is 582.2 μm * 343 μm. The frequency range of the ADPLL is from 4 to 416 MHz. The measurement results show that the ADPLL can achieve a frequency locking in two reference cycles when locking to 376 MHz. The corresponding power consumption is 11.394 mW.