WS4518D

WS4518D 300mA, Single Li-ion Battery Charger WS4518D www.sh-willsemi.com Descriptions The WS4518D is a complete constant-current / constant voltage linear charger for single cell Lithium-Ion batteries. No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The WS4518D automatically terminates the charge cycle when the charge current drops to 3/10 the programmed value after the final float voltage is reached. DFN2X2-6L PROG 1 GND 6 TEMP GND 2 WS4518D 5 CHRGb VCC 3 Expose Pad 4 BAT Pin configuration (Top view) When the input supply (wall adapter or USB supply) is removed, the WS4518D automatically enters a low current state, dropping the battery drain current to less than 0.5u...