DESCRIPTION
The LTC®4006 is a complete constant-current/constant voltage charger controller for 2-, 3- or 4-cell lithium bat teries in a small package using few external components. The PWM controller is a synchronous, quasi-constant frequency, constant off-time architecture that will not generate audible noise even when using ceramic capacitors.

FEATURES
■ Complete Charger Controller for 2-, 3- or 4-Cell
Lithium-Ion Batteries
■ High Conversion Efficiency: Up to 96%
■ Output Currents Exceeding 4A
■ ±0.8% Accurate Preset Voltages: 8.4V, 12.6V, 16.8V
■ Built-In Charge Termination with Automatic Restart
■ AC Adapter Current Limiting Maximizes Charge Rate
■ Automatic Conditioning of Deeply Discharged Batteries
■ Thermistor Input for Temperature Qualified Charging
■ Wide Input Voltage Range: 6V to 28V
■ 0.5V Dropout Voltage; Maximum Duty Cycle: 98%
■ Programmable Charge Current: ±4% Accuracy
■ Indicator Outputs for Charging, C/10 Current Detection and AC Adapter Present
■ Charging Current Monitor Output
■ 16-Pin Narrow SSOP Package

APPLICATION
■ Notebook Computers
■ Portable Instruments
■ Battery-Backup Systems
■ Standalone Li-Ion Chargers