A 5.58nW 32.768kHz DLL-Assisted XO for Real-Time Clocks in Wireless Sensing Applications

📋 论文概要

该论文提出了一种用于无线传感网络实时时钟的超低功耗32.768kHz晶振，通过DLL辅助技术实现了5.58nW的功耗，解决了传统晶振功耗过高的问题，适用于nW级微系统。

💡 主要创新点

• 采用DLL辅助技术替代传统高功耗振荡器结构，大幅降低晶振功耗至5.58nW。
• 通过动态偏置和低功耗电路设计，实现了在32.768kHz频率下的超低功耗运行。

🏷 关键词

📄 原文摘要

There is a growing interest in ultra-low-power wireless microsystems [1]. Synchronization between different nodes in a wireless sensor network plays an important role in the overall node energy budget due to the high power demand of wireless communication. One synchronization approach is to employ a realtime clock (RTC) on each node, with nodes awakening periodically to communicate and re-synchronize. With recent work on ultra-low-power microsystems demonstrating average power consumption of several nW [2], there is a need for ultra-low-power timers that can synchronize communication events and serve as frequency references for radios. Ultra-low-power silicon-based RTCs can consume sub-nW (e.g., 660pW in [3]), but they suffer from high frequency instability. Crystal oscillators (XOs) provide a more constant frequency but at the expense of higher power consumption, typically in the range of µW to 100s of nW. Previous works on low-power XOs

👥 作者与机构

Dongmin Yoon, Dennis Sylvester, David Blaauw

University of Michigan, Ann Arbor, MI