The XB5556A0 with SOT-23-5 is a Battery Management IC manufactured by XySemi. It is RoHS compliant and can help manage all types of lithium-ion batteries, including Li-Ion, Li-Polymer, and LiFePO batteries. It serves as a regulated interface between the battery and charging system, providing battery voltage measurement, battery voltage monitoring, and battery protection includes voltage & temperature over/under-voltage protection, over-current protection, and balancing. Furthermore, it is designed with low internal resistance to minimize power loss and provide high efficiency.