How to Use tp4056: Examples, Pinouts, and Specs

The TP4056 is a lithium-ion battery charger IC manufactured by TP, designed to provide a constant current/constant voltage (CC/CV) charging profile. It is specifically tailored for charging single-cell lithium-ion batteries with high efficiency and safety. The IC integrates features such as thermal regulation, over-voltage protection, and automatic charge termination, making it a reliable and user-friendly solution for battery charging applications.

• Charging single-cell lithium-ion or lithium-polymer batteries
• Power banks and portable battery packs
• Wearable devices and IoT gadgets
• USB-powered charging circuits
• DIY electronics projects

The TP4056 is a compact and versatile IC with the following key specifications:

The TP4056 IC is typically available in an 8-pin SOP package. Below is the pinout and description:

1. Power Supply: Connect a regulated DC power source (e.g., USB 5V) to the VCC pin. Ensure the input voltage is within the range of 4.0V to 8.0V.
2. Battery Connection: Connect the positive terminal of the lithium-ion battery to the BAT pin and the negative terminal to GND.
3. Programming Charging Current: Use a resistor (RPROG) between the PROG pin and GND to set the desired charging current. The charging current can be calculated using the formula: [ I_{CHG} = \frac{1200}{R_{PROG}} ] For example, a 1.2kΩ resistor sets the charging current to 1A.
4. Status Monitoring: Use the CHRG and STDBY pins to monitor the charging status. These pins are open-drain and require pull-up resistors.
5. Thermal Regulation: If required, connect an NTC thermistor to the TEMP pin for battery temperature monitoring. If unused, connect TEMP to GND.

• Heat Dissipation: The TP4056 can generate heat during operation. Ensure proper heat dissipation by using a PCB with adequate thermal management.
• Battery Protection: Use a battery with built-in protection circuitry to prevent over-discharge and over-current conditions.
• Input Voltage: Avoid exceeding the maximum input voltage of 8.0V to prevent damage to the IC.
• Capacitors: Place a 1µF ceramic capacitor close to the VCC pin and a 10µF capacitor near the BAT pin for stable operation.

The TP4056 can be used in conjunction with an Arduino UNO to monitor battery charging status. Below is an example code snippet:

// TP4056 Status Monitoring with Arduino UNO
// Connect CHRG pin to Arduino pin 2 and STDBY pin to Arduino pin 3

const int chrgPin = 2;  // CHRG pin of TP4056
const int stdbyPin = 3; // STDBY pin of TP4056

void setup() {
  pinMode(chrgPin, INPUT);  // Set CHRG pin as input
  pinMode(stdbyPin, INPUT); // Set STDBY pin as input
  Serial.begin(9600);       // Initialize serial communication
}

void loop() {
  int chrgStatus = digitalRead(chrgPin);  // Read CHRG pin status
  int stdbyStatus = digitalRead(stdbyPin); // Read STDBY pin status

  if (chrgStatus == LOW) {
    Serial.println("Battery is charging...");
  } else if (stdbyStatus == HIGH) {
    Serial.println("Battery is fully charged or in standby mode.");
  } else {
    Serial.println("No battery connected or error.");
  }

  delay(1000); // Wait for 1 second before checking again
}

1. Problem: The battery is not charging.

   • Solution: Check the input voltage at the VCC pin. Ensure it is within the range of 4.0V to 8.0V.
   • Solution: Verify the connections to the BAT pin and ensure the battery is properly connected.

2. Problem: The TP4056 IC overheats during operation.

   • Solution: Reduce the charging current by increasing the value of the RPROG resistor.
   • Solution: Improve heat dissipation by using a PCB with thermal vias or a heatsink.

3. Problem: The CHRG and STDBY pins do not provide correct status signals.

   • Solution: Ensure pull-up resistors are connected to the CHRG and STDBY pins.
   • Solution: Verify the connections to the Arduino or other monitoring circuits.

• Can I use the TP4056 to charge multiple batteries in series?

  • No, the TP4056 is designed for single-cell lithium-ion batteries only. Charging multiple cells in series requires a specialized multi-cell charger.

• What happens if the input voltage exceeds 8.0V?

  • Exceeding the maximum input voltage can damage the IC. Always use a regulated power source within the specified range.

• Can I adjust the charging voltage?

  • No, the charging voltage is fixed at 4.2V ± 1% and cannot be adjusted.

• Is the TP4056 suitable for fast charging?

  • The TP4056 supports charging currents up to 1A, which is suitable for most single-cell lithium-ion batteries. For higher currents, consider alternative ICs.

This concludes the documentation for the TP4056.