A Digital PLL With a Stochastic Time-to-Digital Converter

Abstract

A new dual-loop digital phase-locked loop (DPLL) architecture is presented. It employs a stochastic time-to-digital converter (STDC) and a high-frequency delta-sigma dithering to achieve wide PLL bandwidth and low jitter at the same time. The STDC exploits the stochastic properties of a set of latches to achieve high resolution. A prototype DPLL test chip has been fabricated in a 0.13-mum CMOS process, features a 0.7-1.7-GHz oscillator tuning range and a 6.9-ps rms jitter, and consumes 17 mW under 1.2-V supply while operating at 1.2 GHz.