TP4056 lithium battery charging board

## TP4056 main parameters 1. Programmable charging current 1000mA. 2. Constant current/constant voltage operation, with thermal regulation function that maximizes charging rate without danger of overheating. 3. 4.2V precharge voltage with an accuracy of ±1%. 4. Dual output of charging status, no battery and fault status display. ## Mainly used in 1. Can be used for charging single-cell lithium batteries. 2. Portable devices. 3. Charger. 4. Bluetooth, GPS navigator, etc. ## Function description of each pin Pin number Pin name description 1 TEMP Battery temperature detection input 2 PROG Programmable constant current charging current setting terminal 3 GND Ground terminal 4 VCC power terminal 5 BAT battery terminal 6 STDBY battery charging completion indicator terminal 7 CHRG Battery charging indicator terminal 8 CE Chip enable input terminal ## Circuit description Main circuit
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### Different output currents in the output current calculation circuit can be determined through pin 9. The setting resistor and charging current are calculated using the following formula: R PROG=1200/Ibat (error ±10%) The minimum current output is 100mA, and the maximum current output is 1A. ### Status indication description TP4056 has two open-drain status indication output terminals CHRG and STDBY. When the charger is in charging state, CHRG is pulled to low level, and in other states CHRG is in high impedance state; when the battery charging is completed, STDBY is pulled to low level, in other states STDBY is in high impedance state. When the battery is not connected to the charger, CHRG flashes to indicate that no battery is installed. ### Indicator light on and off table: Charging status CHRG STDBY Charging on and off Charging completed off on under voltage, battery temperature is too high, too low and other fault conditions, or no battery access (TEMP use) BAT terminal connected to a 1uF capacitor , no battery flashing (frequency is about 20Hz) on ### Temperature detection The temperature detection function is not used in this circuit, so pin 1 is directly grounded. If you need to use temperature detection, please refer to the data sheet.