A PVT-Insensitive 7-Bit Coarse-Fine Ratio-Metric Digital-to-Time Converter for Fractional-N Phase-Locked Loops in 65-nm CMOS. - Shenjian Zhang; Chenming Zhang; Hao Luo; Shengtao Yi; Xuewei Ding; Zhirui Zong (ISCAS, 2025)