LTC3108 Ultralow Voltage Step-Up Converter and Power Manager FEATURESDESCRIPTION n Operates from Inputs of 20mV The LTC®3108 is a highly integrated DC/DC converter n Complete Energy Harvesting Power ideal for harvesting and managing surplus energy from Management System extremely low input voltage sources such as TEGs (ther- n Selectable VOUT of 2.35V, 3.3V, 4.1V or 5V moelectric generators), thermopiles and small solar cells. n LDO: 2.2V at 3mA The step-up topology operates from input voltages as n Logic Controlled Output low as 20mV. The LTC3108 is functionally equivalent to n Reserve Energy Output the LTC3108-1 except for its unique fixed VOUT options. n Power Good Indicator Using a small step-up transformer, the LTC3108 provides n Uses Compact Step-Up Transformers a complete power management solution for wireless n Small 12-Lead (3mm × 4mm) DFN or 16-Lead sensing and data acquisition. The 2.2V LDO powers an SSOP Packages external microprocessor, while the main output is pro- grammed to one of four fixed voltages to power a wire- APPLICATIONS less transmitter or sensors. The power good indicator n Remote Sensors and Radio Power signals that the main output voltage is within regulation. n Surplus Heat Energy Harvesting A second output can be enabled by the host. A storage n HVAC Systems capacitor provides power when the input voltage source n Industrial Wireless Sensing is unavailable. Extremely low quiescent current and high n Automatic Metering efficiency design ensure the fastest possible charge times n Building Automation of the output reservoir capacitor. n Predictive Maintenance The LTC3108 is available in a small, thermally enhanced All registered trademarks and trademarks are the property of their respective owners. 12-lead (3mm × 4mm) DFN package and a 16-lead SSOP package. TYPICAL APPLICATIONWireless Remote Sensor Application Powered From a Peltier CellVOUT Charge Time 1nF 1:100 5V C1 VSTORE 1000 + + + V 0.1F OUT = 3.3V THERMOELECTRIC LTC3108 C 220µF 6.3V OUT = 470µF 330pF GENERATOR C2 VOUT2 100 PGOOD 20mV TO 500mV PGD 2.2V µP SW VLDO 2.2µF SENSORS 10 TIME (sec) VS2 V 3.3V OUT + RF LINK 470µF 1 VS1 1:100 Ratio VOUT2_EN 1:50 Ratio 3108 TA01a VAUX GND 1:20 Ratio 0 0 50 100 150 200 250 300 350 400 1µF VIN (mV) 3108 TA01b Rev. D Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts