Microsource semiconductor

LP4054H is a complete linear charger for constant current/constant voltage single cell lithium-ion batteries. Its SOT23-5 package and lower external component count make LP4054H very suitable for portable applications. In addition, LP4054H is specifically designed to work with USB power specifications. No external induction resistance is required, as the internal MOSFET structure does not require blocking diodes. Thermal feedback adjusts the charging current to limit mold temperature during high-power operation or high ambient temperatures. The charging voltage is fixed at 4.2V, and the charging current can be externally programmed using a single resistor. After reaching the final float voltage, when the charging current drops to the programmed value of 1.5/10, LP4054H automatically terminates the charging cycle.