What are the precautions for the TP4056 charger with a single-cell Li-ion battery?

The TP4056 is a complete single-cell Li-Ion battery with a constant current/constant voltage linear charger. The SOP8/MSOP8 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, so that the current will be supplied? Arrived 55uA, other features of the TP4056 include battery temperature sensing, undervoltage lockout, automatic recharge, and two LED status pins for charging and termination.

TP4056 pin diagram

TP4056 use precautions

1. TP4056 is packaged in SOP8-PP. In use, the bottom heat sink and PCB board should be soldered well. The bottom heat dissipation area needs to be filled with holes, and the large area copper foil heat dissipation is excellent. Multi-layer PCB plus sufficient vias have a good effect on heat dissipation, and poor heat dissipation may cause the charging current to be reduced by temperature protection. Adding appropriate vias to the heat sink on the back side of the SOP8 also facilitates hand soldering (the solder can be soldered from the back vias to reliably solder the heat sink).

2. TP4056 is used in high current charging (700mA or more), in order to shorten the charging time, it is necessary to increase the heat dissipation resistance, the resistance range is 0.2 ~ 0.5Ω. The customer selects the appropriate resistor size based on usage.

3. In the TP4056 application, the 10u capacitor position of the BAT end is superior to the BAT end of the chip, and should not be too far.

4. In the TP4056 test, the BAT terminal should be directly connected to the battery. The ammeter cannot be connected in series. The ammeter can be connected to the VCC terminal.

5. In order to ensure reliable use under various conditions, to prevent chip damage caused by spikes and glitch voltage, it is recommended to connect a 0.1u ceramic capacitor to the BAT terminal and the power input terminal, and it is very close to the TP4056 chip during wiring.

6. TP4056 cannot be reversed battery will burn the tablets. There is anti-lithium battery reverse connection protection circuit.

Please use 4.4v~5v power supply for power supply. The 4.2k~10k resistor is randomly distributed. It may be 4.2k, or 5.1k, or 10k. It can be used. The Rx is a voltage-regulating resistor. The initial state can be short-circuited with a wire before it is the corresponding resistance is taken according to its cutoff voltage.

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