A 0.1–1.5 GHz all-digital phase inversion delay-locked loop

Abstract

An all-digital, wide-range phase inversion delay-locked loop (PIDLL) with a high-resolution duty-cycle corrector (DCC) is presented. The proposed PIDLL utilizes a new phase inversion scheme to reduce the total number of delay elements (DEs) in the digitally controlled delay line (DCDL) by approximately one-half, enabling shorter locking times, lower power consumption, reduced jitter performance, and a smaller area, while maintaining a wide operating frequency range. To achieve high delay resolution and linear delay characteristics, a three-stage DCDL using a new area-efficient digital feedback delay element (FDE) is proposed. The FDE is also utilized to implement a new DCC that obtains a duty-cycle error of less than ±0.85% over a 30-70% input duty-cycle range. The proposed DCC-equipped PIDLL is implemented in a 0.13-μm CMOS process, occupies an area of 0.11 mm2, and operates over a wide frequency range of 0.1-1.5 GHz. It dissipates power of 5.9 mW from a 1.2 V supply at 1 GHz and exhibits a peak-to-peak output clock jitter of 11.25 ps at 1.5 GHz.