The XT4051K421MR-G is a power management integrated circuit (PMIC) manufactured by Natlinear and designed for battery management. It is packaged in a SOT-23-5L RoHS compliant package which is lead-free. The circuit provides high-efficiency current and voltage regulation for a range of battery chemistries. It features an adjustable battery charging voltage, automatic charge termination, selectable charge current and an SC/TO charge algorithm. The device also features an on-chip safety circuit with over temperature, over current and over voltage protection. Additional features include battery charge status monitoring, reverse current blocking, and supply independent battery top-off. The XT4051K421MR-G is suitable for applications such as portable medical devices, smartphones, tablets, cameras and other battery powered devices.