A Wide-Range, Low-Power, All-Digital Delay-Locked Loop With Cyclic Half-Delay-Line Architecture

A 3 MHz-to-1.8 GHz, 94 μW-to-9.5 mW, all-digital delay-locked loop (ADDLL) using 65-nm CMOS technology is presented. In this paper, a cyclic half-delay-line architecture that uses the same type of delay lines for cyclic delay determination and coarse locking is proposed and used to achieve the design goals of small footprint and fast locking for a large operating frequency range. In addition, a new delay structure is developed for the cyclic delay units and coarse delay line. In addition to clock gating, which is used to reduce power consumption in the lock-in state regardless of the clock frequency, the automatic bypassing of the cyclic operation is developed and used to reduce power consumption during high-frequency operation. Through the use of proposed techniques, the active area is reduced to only 0.0153 mm ², and the operating frequency range is from 3 MHz to 1.8 GHz. The measurement results show that the proposed ADDLL achieves a peak-to-peak jitter of 3 ps with 9.5 mW power consumption when operated at 1.8 GHz.