LTC4007-1

LTC4007-1 4A, High Efficiency, Li-Ion Battery Charger Features Description n Charger Controller for 3- or 4-Cell Lithium-Ion Batteries n High Conversion Efficiency: Up to 96% n Output Currents Exceeding 4A n ±0.8% Charging Voltage Accuracy n Built-In Charge Termination for Li-Ion Batteries n AC Adapter Current Limiting Maximizes Charge Rate* n Thermistor Input for Temperature Qualified Charging n Wide Input Voltage Range: 6V to 28V n 0.5V Dropout Voltage; Maximum Duty Cycle: 98% n Programmable Charge Current: ±4% Accuracy n Indicator Outputs for Charging, C/10 Current Detection, AC Adapter Present, Low Battery, Input Current Limiting and Faults n Charging Current Monitor Output n Available in a 24-Pin 4mm × 5mm QFN Package Applications n Notebook Computers n Portable Instruments n Battery-Backup Systems n Li-Ion Chargers The LTC®4007-1 is a constant-current/constant-voltage charger controller for 3- or 4-cell lithium-ion batteries. The PWM controller uses a synchronous, quasi-constant frequency, constant off-time architecture that will not generate audible noise even when using ceramic capacitors. Charging current is programmable to ±4% accuracy using a programming resistor. Charging current can also be monitored as a voltage across the programming resistor. The output float voltage is pin programmed for cell count (3 cells or 4 cells) and chemistry (4.2V/4.1V). A timer, programmed by an external resistor, sets the total charge time. The LTC4007-1 includes a thermistor in...