A 2.8-3.8-GHz Low-Spur DTC-Based DPLL With a Class-D DCO in 65-nm CMOS

Research output: Contribution to journalArticle


We present a digital phase-locked loop (DPLL) operating from 2.8 to 3.8 GHz with an on-chip 40-MHz reference crystal oscillator. The DPLL makes use of a class-D digitally controlled oscillator and a digital-to-time converter with a single-bit (bang-bang) phase detector. The DPLL displays an excellent behavior in terms of in-band fractional spurs, which are consistently below -65 dBc across the tuning range, thanks to a number of digital correction algorithms running in the background. The 65-nm CMOS DPLL consumes 18.2 mW for an in-band phase noise of -102 dBc/Hz at 100-kHz offset.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Electrical Engineering, Electronic Engineering, Information Engineering


  • Bang-bang phase detector (BBPD), class-D, Detectors, digital phase-locked loop (DPLL), digital-to-time converter (DTC), digitally controlled oscillator (DCO), Frequency conversion, least mean square (LMS), Phase locked loops, Phase noise, phase noise, pre-distorter, Solid state circuits, spurs, time-to-digital converter (TDC)., Tuning
Original languageEnglish
Pages (from-to)1010-1012
JournalIEEE Microwave and Wireless Components Letters
Issue number11
Early online date2017 Sep 27
Publication statusPublished - 2017 Nov
Publication categoryResearch