How to Use TP4056: Examples, Pinouts, and Specs

The TP4056 is a lithium-ion battery charger IC manufactured by Electrokit. It is designed to provide a constant current/constant voltage (CC/CV) charging profile, making it ideal for charging single-cell lithium-ion batteries. The IC integrates several safety features, including over-voltage protection, under-voltage lockout, and thermal regulation, ensuring safe and efficient charging.

• Charging single-cell lithium-ion or lithium-polymer batteries
• Power banks and portable battery packs
• DIY electronics projects requiring rechargeable batteries
• Battery-powered IoT devices
• Wearable electronics

The TP4056 is a highly efficient and compact charging IC. Below are its key technical details:

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

The TP4056 is straightforward to use in a circuit. Below are the steps and considerations for proper usage:

1. Power Supply: Connect a DC power source (4.0V to 8.0V) to the VCC pin. Ensure the power source can supply sufficient current for the charging process.
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 charging current. The charging current (ICHG) 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 Indicators: Connect LEDs to the CHRG and STDBY pins (with appropriate current-limiting resistors) to monitor the charging status:
   • CHRG pin: Low when charging is in progress.
   • STDBY pin: Low when charging is complete.
5. Temperature Monitoring: Optionally, connect an NTC thermistor to the TEMP pin for battery temperature monitoring. If unused, connect TEMP to GND.

• Thermal Management: Ensure proper heat dissipation, especially when charging at high currents. Use a PCB with adequate thermal vias and copper planes.
• Battery Protection: Use a protection circuit module (PCM) with the battery 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.
• Current Limiting: Select the RPROG resistor carefully to avoid overcharging the battery.

The TP4056 can be used in conjunction with an Arduino UNO to monitor the 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 connected to Arduino pin 2
const int stdbyPin = 3; // STDBY pin of TP4056 connected to Arduino pin 3

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("Charging in progress...");
  } else if (stdbyStatus == LOW) {
    Serial.println("Charging complete.");
  } else {
    Serial.println("No battery connected or standby mode.");
  }

  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 4.0V to 8.0V range.
   • Solution: Verify the RPROG resistor value to ensure the charging current is set correctly.
   • Solution: Ensure the battery is properly connected to the BAT and GND pins.

2. Problem: The IC overheats during operation.

   • Solution: Reduce the charging current by increasing the RPROG resistor value.
   • Solution: Improve PCB thermal management by adding copper planes or heat sinks.

3. Problem: Status LEDs are not functioning.

   • Solution: Check the connections and current-limiting resistors for the LEDs.
   • Solution: Verify the CHRG and STDBY pin voltages during operation.

• Can the TP4056 charge multiple batteries in series?

  • No, the TP4056 is designed for single-cell lithium-ion batteries only.

• What happens if the input voltage exceeds 8.0V?

  • Exceeding 8.0V can damage the IC. Always use a regulated power supply within the specified range.

• Can I use the TP4056 without the TEMP pin?

  • Yes, if temperature monitoring is not required, connect the TEMP pin to GND.

• How do I adjust the charging current?

  • Use the formula ( I_{CHG} = \frac{1200}{R_{PROG}} ) to calculate the required RPROG resistor value.

This concludes the TP4056 documentation. For further assistance, refer to the manufacturer's datasheet or contact Electrokit support.