The TP4056 is a complete single-cell Li-Ion battery with a constant current/constant-voltage linear charger. The SOP40 package with the heatsink on the bottom of the TP4056 and fewer 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, reducing the supply current to 55uA.
Other features of the TP4056 include battery temperature sensing, Undervoltage lockout, automatic recharge, LED status pins for charging, and termination.