LTC4055 Datasheet | Linear Technology

LTC4055/LTC4055-1 USB Power Controller and Li-Ion Charger Features DESCRIPTION n Charges Single-Cell Li-Ion Batteries Directly from USB Port n Load Dependent Charging Guarantees USB Input Current pliance n Automatic Battery Switchover When Input Supply is Removed n Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charging Rate Without Risk of Overheating- n Selectable 500m A/100m A Current Limit n Low Loss Full Power Path™ Control with Ideal Diode Operation (Reverse Current Blocking) n Preset 4.2V Charge Voltage with 0.8% Accuracy (4.1V for LTC4055-1) n 4.1V Float Voltage (LTC4055-1) Improves Battery Life and High Temperature Safety Margin n USB-pliant Suspend Mode n Programmable Charge Current and Termination Timer n Soft-Start Limits Inrush Current n NTC Thermistor Input for Temperature Qualified Charging n Tiny (4mm × 4mm × 0.75mm) QFN Package APPLICATIONS n Portable USB Devices: Cameras, MP3 Players, PDAs L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Power Path is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. - Protected by U.S. Patent, including 6522118. The LTC®4055/LTC4055-1 are USB power manager and Li-Ion battery chargers designed to work in portable battery-powered applications. The parts manage and limit the total current used by the USB peripheral for operation and battery charging. Depending on the state of the current select pin (HPWR), total input current can be limited to either 100m A or 500m A. The voltage drop from the USB supply or battery to the USB peripheral is typically less than 100m V at 400m A and 20m V at 80m A. Other management Features include: automatic switchover to battery when input is removed, inrush current limiting, reverse current blocking, undervoltage lockout and thermal shutdown. The LTC4055/LTC4055-1 include a plete constantcurrent/constant-voltage linear charger for single-cell Li-ion...