A Sub-nW 80mlx-to-1.26Mlx Self-Referencing Light-to-Digital Converter with AlGaAs Photodiode

📋 论文概要

提出了一种亚纳瓦功耗、自参考的光数字转换器，采用AlGaAs光电二极管，可测量80mlx至1.26Mlx的宽范围光强，用于可穿戴设备的累计光暴露监测。

💡 主要创新点

• 实现亚纳瓦级功耗的光数字转换，极大延长可穿戴设备电池寿命。
• 采用自参考架构，消除环境温度与工艺变化对测量精度的影响。
• 宽动态范围覆盖从弱光到强光（80mlx-1.26Mlx），适应多种光照场景。

🏷 关键词

📄 原文摘要

Wearable sensors are increasingly common and continue to grow more diverse in their sensing modalities, ranging from glucose to heart rate monitoring. One compelling sensing modality for wearable sensors is cumulative light exposure. For instance, reduced light exposure exacerbates depression, while high levels of sunlight exposure are well known as the primary cause of skin cancer. In order for wearable sensors to determine how much light radiation the skin is receiving, a light-to-digital converter (LDC) is needed to both measure instantaneous light intensity and record the total accumulated light energy. LDCs targeting wearable devices will have tight constraints on area (cost) and power. At the same time, the wide dynamic range of light (~106) from 0.1lx to 100klx places difficult performance requirements on the LDC. Previous LDCs integrate photodiode current and use a transimpedance amplifier followed by ADC conversion [1-2],

👥 作者与机构

Wootaek Lim, Dennis Sylvester, David Blaauw

University of Michigan, Ann Arbor, MI