LTC4070

FEATURES n Low Operating Current (450nA) n 1% Float Voltage Accuracy Over Full Temperature and Shunt Current Range n 50mA Maximum Internal Shunt Current (500mA with External PFET) n Pin Selectable Float Voltage Options: 4.0V, 4.1V, 4.2V n Ultralow Power Pulsed NTC Float Conditioning for Li-Ion/Polymer Protection n Suitable for Intermittent, Continuous and Very Low Power Charging Sources n Low and High Battery Status Outputs n Simple Low Voltage Load Disconnect Application n Thermally Enhanced, Low Profile (0.75mm) 8-Lead (2mm × 3mm) DFN and MSOP Packages APPLICATIONS n Low Power Li-Ion/Polymer Battery Back-Up n Solar Power Systems with Back-Up n Memory Back-Up n Embedded Automotive n Thin Film Batteries n Energy Scavenging/Harvesting All registered trademarks and trademarks are the property of their respective owners. LTC4070 Li-Ion/Polymer Shunt Battery Charger System DESCRIPTION The LTC®4070 allows simple charging of Li-Ion/Polymer batteries from very low current, intermittent or continuous charging sources. The 450nA to 50mA operating current makes charging possible from previously unusable sources. With the addition of an external pass device, shunt current may be boosted to 500mA. Stacked cell high voltage battery packs are inherently balanced with shunt charging. 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 uniqu...