TP4056 - 4.2V 1A Standalone Linear Li-ion Battery Charger with Thermal Regulation SOP8

Datasheet

The TP4056 is a complete single-cell Li-Ion battery with a constant current / constant voltage linear charger. The SOP8 package with heatsink on the bottom and a small number of external components make the TP4056 ideal for portable applications. The TP4056 is suitable for USB  power and adapter power supplies. Due to the internal PMOSFET architecture and anti-reverse charging path, no external isolation diodes are required. Thermal feedback automatically adjusts the charge current to limit chip temperature during high power operation or high ambient temperature conditions. The charging voltage is fixed at 4.2V , and the charging current can be externally set by a resistor. When the charging current drops to the set value of 1/10 after reaching the final float voltage , the TP4056 will automatically terminate the charging cycle.

When the input voltage (AC adapter or USB  power) is removed, the TP4056  automatically enters a low current state, reducing the battery leakage current to less than 2uA . The TP4056 can also be placed in shutdown mode when there is a power supply to reduce the supply current to 55uA. Other features of the TP4056 include battery temperature sensing, undervoltage lockout, automatic recharge, and two LED status pins for charging and termination .