TI公司的BQ25504是一款最新集成纳米智能能源收集电源管理解决方案，本方案非常适合有特殊需要的超低功耗的应用环境。该产品是专门设计来有效地获取和管理微瓦和毫瓦的电力，电力通常来自各种光伏太阳能直流源或热电动发电机。BQ25504是第一种面向产品和系统实现高效的执行转换器或充电器，例如应用在对操作功耗有严格的需求无线电传感器网络。采用BQ25504设计的DC-DC升压转换器/充电器，只需要毫瓦的电力就可以工作。本文通过总结BQ25504器件的特点，介绍器件、特性、应用方向及内部结构框图，并给参考设计实例原理图、制板图及元器件清单。
The bq25504 is the first of a new family of intelligent integrated energy harvesting Nano-Power management solutions that are well suited for meeting the special needs of ultra low power applications. The product is specifically designed to efficiently acquire and manage the microwatts (μW) to miliwatts (mW) of power generated from a variety of DC sources like photovoltaic (solar) or thermal electric generators. The bq25504 is the first device of its kind to implement a highly efficient boost converter/charger targeted toward products and systems, such as wireless sensor networks (WSN) which have stringent power and operational demands. The design of the bq25504 starts with a DCDC boost converter/charger that requires only microwatts of power to begin operating.

BQ25504主要特性：
Ultra Low Power With High Efficiency DC/DC Boost Converter/Charger
–  Continuous Energy Harvesting From Low Input Sources: VIN ≥ 80 mV(Typical)Ultra Low Quiescent Current: IQ < 330 nA (Typical)
–  Cold-Start Voltage: VIN ≥ 330 mV (Typical)Programmable Dynamic Maximum Power Point Tracking (MPPT)
–  Integrated Dynamic Maximum Power Point Tracking for Optimal Energy Extraction From a Variety of Energy Generation Sources Input Voltage Regulation Prevents Collapsing Input Source Energy Storage
–  Energy can be Stored to Re-Chargeable Li-ion Batteries, Thin-film Batteries, Super-Capacitors, or Conventional Capacitors Battery Charging and Protection
–  User Programmable Undervoltage and Overvoltage Levels
–  On-Chip Temperature Sensor with Programmable Overtemperature Shutoff Battery Status Output
–  Battery Good Output Pin
–  Programmable Threshold and Hysteresis
–  Warn Attached Microcontrollers of Pending Loss of Power
–  Can be Used to Enable/Disable System Loads

BQ25504应用：
• Energy Harvesting
• Solar Charger
• Thermal Electric Sources Generator (TEG) Harvesting
• Wireless Sensor Networks (WSN)
• Industrial Monitoring
• Environmental Monitoring
• Bridge and Structural Health Monitoring (SHM)
• Smart Building Controls
• Portable and Wearable Health Devices
• Entertainment System Remote Controls
 
图1. BQ25504方框图

BQ25504参考设计主要特性：
• Evaluation module for bq25504
• Ultra low power boost converter/charger with battery management for energy harvester applications
• Resistor-programmable settings for under voltage, over voltage providing flexible battery management;
POTs Included for fine tuning the settings (not populated)
• Programmable push-pull output Indicator for battery status (VBAT_OK)
• Test points for key signals available for testing purpose – easy probe hook-up.
• Jumpers available – easy to change settings

BQ25504设计原理图：

图2. BQ25504设计原理图

BQ25504设计方案材料清单：


PCB元件布局图：