A Micropower Battery Current Sensor with ±0.03% (3σ) Inaccuracy from -40 to +85°C

📋 论文概要

本文提出了一种用于电池监测的微功耗电流传感系统，由校准分流电阻、ΔΣ ADC和动态带隙参考构成。通过动态误差校正和数字温度补偿技术，在-40至+85°C范围内实现了0.03%的增益误差和10μA偏移，精度比使用片外参考的方案提升3倍。

💡 主要创新点

• 采用动态误差校正（如斩波）和数字温度补偿，在宽温度范围内实现高精度电流测量，无需外部参考。
• 片上集成动态带隙参考（BGR），具有低温度系数，替代传统片外精密参考，降低功耗和成本。
• 使用ΔΣ ADC与校准分流电阻结合，实现微功耗下的高分辨率电流检测，适用于便携式电池监控。

🏷 关键词

📄 原文摘要

Infineon Technologies, Villach, Austria 1 2 This paper presents a micropower current-sensing system (CSS) for battery monitoring, which consists of a calibrated shunt resistor, a ΔΣ ADC, and a dynamic bandgap reference (BGR). For currents ranging from 0 to 1A over the industrial temperature range (-40°C to +85°C), it exhibits 10μA offset and ±0.03% (3σ) gain error, which is a 3× improvement on systems with off-chip external references [1,2]. This level of accuracy is achieved by the use of dynamic error-correction techniques, digital temperature compensation, and an onchip dynamic BGR, whose spread is corrected by a single room-temperature trim. A block diagram of the CSS is shown in Fig. 22.4.1. Battery current Ibat flowing through a shunt resistor Rshunt gives rise to a voltage drop Vshunt, which is then digitized by a switched-capacitor (SC) ΔΣ ADC. In order to cope with the specified 1.35V (minimum) supply voltage, the ADC generates a dynamic reference

👥 作者与机构

Saleh Heidary Shalmany1, Dieter Draxelmayr2, Kofi A.A. Makinwa1

Delft University of Technology, Delft, The Netherlands,