DESCRIPTIOn

The LTC4002 is a complete battery charger controller for one(4.2V) or two (8.4V) cell lithium-ion batteries. With a 500kHz switching frequency, the LTC4002 provides a small, simple and efficient solution to fast charge Li-lon batteries from a wide range of supply voltages. An external sense resistor sets the charge current with±5% accuracy.An internal resistor divider and precision reference set the final float voltage to 4.2V per cell with ±1% accuracy.When the input supply is removed, the LTC4002automati-cally enters a low current sleep mode, dropping the battery drain current to 10uA. An internal comparator detects the near end-of-charge condition while an internal timer sets the total charge time and terminates the charge cycle. After the charge cycle ends, if the battery voltage drops below4.05V per cell,a new charge cycle will automatically begin.The LTC4002 is available inthe 8-lead S0 and 10-leadDFN packages.

FERTURES

■Wide Input Supply Range:

4.7V to 22V-4.2 Version8.9V to 22V-8.4 Version High Efficiency Current Mode PWM Controller with

500kHz Switching Frequency

■±1% Charge Voltage Accuracy End-of-Charge Current Detection Output

■3 Hour Charge Termination Timer aConstant Switching Frequency for Minimum Noise

■±5%Charge Current Accuracy

■Low 10uA Reverse Battery Drain Current

■Automatic Battery Recharge Automatic Shutdown When Input Supply is Removed

■Automatic Trickle Charging of Low Voltage Batteries Battery Temperature Sensing and Charge Qualification Stable with

Ceramic Output Capacitor

■8-Lead S0 and 10-Lead DFN Packages

APPLICATIOnS
■Portable Computers
■Charging Docks
■Handheld Instrumen

Feature

Applications