In summary, the LTC4070 is designed to charge Li-Ion/Polymer batteries from very low current charging sources. The 450nA to 50mA operating current makes charging possible from previously unusable sources. With its low operating current, the LTC4070 is well-suited to charge thin film batteries in energy harvesting applications where charging sources may be intermittent or very low power. The unique architecture of the LTC4070 allows for an extremely simple battery charger solution, requiring just one external resistor. The LTC4070 offers a pin-selectable float voltage with 1% accuracy across the full range of operating temperature and shunt current. The integrated thermal battery qualifier extends battery lifetime and improves reliability by automatically reducing the battery float voltage at NTC thermistor temperatures above 40°C. The device is offered in two thermally-enhanced packages; a compact low profile (0.75mm) 8-lead (2mm x 3mm) DFN, and an 8-lead MSOP package.