A Calibration-Free Ring-Oscillator PLL With Gain Tracking Achieving 9% Jitter Variation Over PVT

• Published in: IEEE transactions on circuits and systems. I, Regular papers Regular papers, 2020-11, Vol.67 (11), p.3753-3763
• Main Authors: Yang, Xiaofeng, Chan, Chi-Hang, Zhu, Yan, Martins, Rui Paulo
• Format: Article
• Language: English
• Subjects: Bandwidth; Broadband; Calibration; calibration-free; Circuits; Clocks; CMOS; discrete-time; Filtration; gain tracking; Jitter; open-loop; Performance degradation; Phase locked loops; Phase noise; phase noise cancellation (PNC); phase-locked loop (PLL); PVT; Realignment; reference spur; ring voltage-controlled oscillator (RVCO); Switches; Tracking; Vibration; Voltage-controlled oscillators
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2020.3013625

This paper presents a calibration-free and low-jitter phase-locked loop (PLL) with small performance degradation over PVT. We introduce an open-loop discrete-time phase noise cancellation (OPDTPNC) technique to achieve a wideband filtering and circuit inner-gain-tracking for PVT stabilization. The OPDTPNC is an effective phase realignment that enables a filtering bandwidth ~1/4 of the reference clock frequency. Besides, with the common structures and PVT tracking bias for sampler and corrector of the OPDTPNC, the prototype PLL maintains its low jitter under a wide range of PVT variations. Eventually, by cascading a Type-II PLL with the OPDTPNC, the proposed hybrid PLL attains the benefits of both Type-II PLL and injection-locked clock multiplier (ILCM). Fabricated in 28-nm CMOS with an active area of 0.023mm 2 it consumes 4.1 mV from a 1 V supply with a reference spur of -63 dBc. The measured rms jitter of the 2.4 GHz PLL is 248 fs and 686 fs with and without OPDTPNC, respectively. When the temperature, supply and loop gain vary from 0 to 100°C, ±5%, and 6dB, respectively, the jitter performance only degrades less than 9%.