Energy-Efficient Cyclic-Coupled Ring Oscillator With Delay-Based Injection Locking

Abstract

This paper presents a new tristate-based delay cell to realize the recently proposed delay-based injection locking in ring oscillators. The circuit is then applied to implement a cycliccoupled ring oscillator (CCRO). Compared to an inverter-based CCRO with multi-drive injection, the proposed circuit eliminates the static short-circuit current drawn from the supply when drive circuits are in conflicting logic states, thus reducing the power consumption of the CCRO. The functionality and improved energy efficiency of the proposed circuit is demonstrated with circuit simulations of a CCRO implemented in a 28-nm CMOS process. The CCRO employing the proposed technique achieves up to 25% lower power consumption and over 20% lower powerdelay product (PDP) compared to the inverter-based CCRO.Index Terms-cyclic-coupled ring oscillator (CCRO), timedomain, time resolution, sub-gate-delay, time-to-digital converter.

Design and analysis of a low phase noise low power ring-VCO

“…Phase-locked loops (PLLs) play a significant part in handheld mobile communication equipment for Internet of Things. The application of wireless communication technology has promoted the development of PLLs with low jitter, small area, and low power [1,2,3,4,5]. Voltage-controlled oscillators (VCOs) are the key module of PLLs, which must possess the characteristics of low power and low phase noise to meet the needs of the low power 802.11ah standard for Internet of Things [6,7,8,9,10,11], i.e.…”