LTC4001-1 Datasheet | Linear Technology

LTC4001-1 2A Synchronous Buck Li-Ion Charger Features Low Power Dissipation n 2A Maximum Charge Current n No External MOSFETs, Sense Resistor or Blocking Diode Required n Remote Sensing at Battery Terminals n Programmable Charge Termination Timer n Preset 4.1V Float Voltage with ±0.5% Accuracy .. n 4.1V Float Voltage Improves Battery Life and High Temperature Safety Margin n Programmable Charge Current Detection/ Termination n Automatic Recharge n Thermistor Input for Temperature Qualified Charging n patible with Current Limited Wall Adapters n Low Profile 16-Lead (4mm × 4mm) QFN Package n DESCRIPTION The LTC®4001-1 is a 2A Li-Ion battery charger intended for 5V wall adapters. It utilizes a 1.5MHz synchronous buck converter topology to reduce power dissipation during charging. Low power dissipation, an internal MOSFET and sense resistor allow a physically small charger that can be embedded in a wide range of handheld applications. The LTC4001-1 includes plete charge termination circuitry, automatic recharge and a ±1% 4.1V float voltage. Input short-circuit protection is included so no blocking diode is required. This 4.1V version of the standard LTC4001 is intended for applications which will be operated or stored above approximately 60°C. Under these conditions, the reduced float voltage will trade-off initial cell capacity for the benefit of increased capacity retention over the life of the battery. A reduced float voltage also minimizes swelling in prismatic and polymer cells, and avoids open CID (pressure fuse) in cylindrical cells. Battery charge current, charge timeout and end-of-charge indication parameters are set with external ponents. Additional Features include shorted cell detection, temperature qualified charging and overvoltage protection. The LTC4001-1 is available in a low profile (0.75mm) 16-lead (4mm × 4mm) QFN package. APPLICATIONS n n n n n Handheld Battery-Powered Devices Handheld puters Charging Docks and Cradles...