原标题：Linear LTC3107超低电压能量收集解决方案

　　Linear公司的LTC3107是高度集成的DC/DC转换器,能从极低电压输入源如热电发生器和热电耦等收集和管理多余能量,以延长低功耗无线系统的电池寿命.输入电压可低至20mV,输出电压2.2V LDO,VOUT能跟踪电池电压,采用标准升压变压器,主要用在工业无线接点,遥控传感器和无线电电源,HVAC,自动读表,建筑物自动化和安全系统等.本文介绍了LTC3107主要特性,框图和典型应用电路以及演示板DC2103A电路图和材料清单.

　　LTC3107 - Ultra-Low Voltage Energy Harvester and Primary Battery Life Extender

　　The LTCR3107 is a highly integrated DC/DC converter designed to extend the life of a primary battery in low power wireless systems by harvesting and managing surplus energy from extremely low input voltage sources such as TEGs (Thermoelectric Generators) and thermopiles. The step-up topology operates from input voltages as low as 20mV. Using a small step-up transformer, the LTC3107 provides a complete power management solution for typical wireless sensor applications that operate from a primary battery. The 2.2V LDO can be used to power an external microprocessor, while the main output voltage automatically adapts to match the voltage of the primary battery. The LTC3107 seamlessly transitions from battery power to harvested power whenever harvested energy is available, extending the life of the battery. The BAT_OFF indicator can be used to track battery usage. An optional storage capacitor accumulates excess harvested energy, further extending battery life.

　　The LTC3107 is available in a small, thermally enhanced 10-lead (3mm × 3mm) DFN package.

　　LTC3107主要特性:

　　Thermal Energy Harvesting Assisted Power Management System

　　VOUT Tracks the Primary Battery Voltage

　　2.2V LDO Output

　　Reserve Energy Output, Clamped to 4.3V

　　Operates from Inputs as Low as 20mV

　　Battery In-Use Indicator (BAT_OFF)

　　IQ from Battery:

　　80nA When Energy Harvesting

　　6μA No Energy Harvesting

　　Standard, Compact Step-Up Transformer

　　Small, Thermally Enhanced 10-lead (3mm × 3mm) DFN package

　　LTC3107应用:

　　Industrial Wireless Sensing

　　Remote Sensor and Radio power

　　HVAC

　　Automatic Metering

　　Building Automation, Security

　　Predictive Maintenance, Condition Monitoring

　　图1. LTC3107框图

　　图2. LTC3107遥控传感器应用电路图:热能收集扩展电池寿命

　　图3. LTC3107热电耦电池寿命扩展器电路图

　　图4. LTC3107 3.6V室内光太阳能电池寿命扩展器电路图

　　图5. LTC3107热电耦和太阳能双输入能量收集电路图

　　演示板DC2103A

　　Demonstration circuit 2103A featuring the LTCR3107 is a highly integrated DC/DC converter designed to extend the life of a primary battery in low power wireless systems by harvesting and managing surplus energy from extremely low input voltage sources such as thermoelectric generators (TEG). The step-up topology operates from input voltages as low as 20mV.

　　The DC2103A demonstration circuit has been optimized for low start-up voltage with a 100:1 turns ratio transformer.

　　For applications where it is desirable to trade-off a higher start-up voltage for higher current, a lower turns ratio transformer can be used. Refer to the LTC3107 data sheet for more information.

　　The LTC3107 is designed to accumulate and manage energy from low voltage and low impedance sources while providing battery backup with seamless transitions between Energy Harvesting (EH) and battery power.

　　By utilizing the EH source when it is available, the life of the battery can be extended by only taking energy from the battery only when necessary. The battery backup also ensures continuous power to the load. The demonstration circuit has been set up with battery terminals to allow for different battery configurations to be used. Please consult the schematic for proper switch positioning. Space is provided, and alternate part footprints have been built into the PCB to allow experimentation with larger capacitors and different battery types for more energy storage.

　　Refer to the data sheet for more information including equations to properly size the output capacitors for a given application.

　　The DC2103A demo board also incorporates a connector (J1) which can be used to connect to a Dust NetworksR mote demo board.

　　图6. 演示板DC2103A外形图:上:顶部;下:底部

　　演示板DC2103A材料清单: