A 3.6-GHz Type-II Sampling PLL With a Differential Parallel-Series Double-Edge S-PD Scoring 43.1-fsRMSJitter, −258.7-dB FOM, and −75.17-dBc Reference Spur

This article presents a low-jitter and low-spur type-II sampling phase-locked loop (S-PLL). The innovative introduction of a differential parallel-series double-edge sampling phase detector (S-PD) achieves a high phase-detection gain and reduces the S-PLL in-band phase noise (PN). Incorporating a transformer-based harmonic-rich shaping voltage-controlled oscillator (VCO), the proposed S-PLL prototyped in a 65-nm CMOS, operates at 3.6 GHz and scores an integrated jitter of 43.1 fsrms integrated from 1 kHz to 100 MHz, it also exhibits a jitter-power figure-of-merit (FOM) of −258.7 dB. The measured reference (REF) spur is −80.34 dBc at $f_{\mathrm {REF}}$ and −75.17 dBc at $2f_{\mathrm {REF}}$ , respectively.