A Low-Spur Fractional-N PLL Based on a Time-Mode Arithmetic Unit

This article introduces a low-jitter low-spur fractional-N phase-locked loop (PLL) adopting a new concept of a time-mode arithmetic unit (TAU) for phase error extraction. The TAU is a time-signal processor that calculates the weighted sum of input time offsets. It processes two inputs - the period of a digitally controlled oscillator (DCO)...

A Low-Noise Fractional-N Digital Frequency Synthesizer With Implicit Frequency Tripling for mm-Wave Applications

In this paper, we propose a 60-GHz fractional-N digital frequency synthesizer aimed at reducing its phase noise (PN) at both the flicker (1/f ³ ) and thermal (1/f ² ) regions while minimizing its power consumption. The digitally controlled oscillator (DCO) fundamentally resonates at 20 GHz and co-generates a strong...

An On-Chip Self-Characterization of a Digital-to-Time Converter by Embedding it in a First-Order ΔΣ Loop

To characterize an on-chip programmable delay in a low-cost and high-resolution manner, a built-in self-test based on a first-order ΔΣ time-to-digital converter with self-calibration is proposed and implemented in TSMC 28-nm CMOS. The system is self-contained, and only one digital clock is needed for the measurements. A...