A 3 GHz DLL-based clock generator with stuck locking protection

This study presents a 3-GHz DLL-based clock generator with stuck locking protection. In this paper, a proposed duty cycle corrector solves the problem of the sensitivity to half transparent (HT) architecture and the stuck locking error in the DLL simultaneously. Based on the frequency-multiplied technique, the multiphase DLL architecture synthesizes a 3-GHz output clock. The post-layout simulation results are based on TSMC 0.18 μm 1P6M CMOS process. The proposed architecture locks into the input frequency of 250 MHz. Operating at the 3-GHz frequency multiplier output, the simulated peak-to-peak jitter is 2.94 ps and 31.17 ps for the 250-MHz locked frequency and 3-GHz synthesized frequency, respectively. The chip area is less than 0.745 × 0.745 mm² and the power consumption is 20.9 mW at a supply of 1.8 V.