XT4054

XT4054 Standalone Linear Li-Ion Battery Charger with Thermal Regulation ■ General Description The XT4054 is a complete constant-current /constant -voltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the XT4054 ideally suited for portable applications. Furthermore, the XT4054 is specifically designed to work within USB power specifications. 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 XT4054 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the XT4054...