How to Use TP4100 With DC Jack: Examples, Pinouts, and Specs

The TP4100 is a versatile power management integrated circuit (IC) designed for efficient voltage regulation and battery charging. It features a built-in DC jack, making it convenient for applications requiring a reliable and straightforward power input interface. The TP4100 is widely used in battery-powered devices, portable electronics, and embedded systems due to its high efficiency and robust design.

• Lithium-ion (Li-ion) and lithium-polymer (LiPo) battery charging
• Power supply regulation for embedded systems
• Portable electronic devices
• DIY electronics projects
• Applications requiring a DC jack for easy power input

• Input Voltage Range: 5V to 26V DC
• Charging Voltage: Configurable up to 4.2V (single-cell Li-ion/LiPo batteries)
• Charging Current: Adjustable up to 2A
• Efficiency: Up to 92%
• Built-in Protections: Overvoltage, overcurrent, and thermal protection
• Operating Temperature Range: -40°C to +85°C
• DC Jack Input: Standard 5.5mm x 2.1mm barrel jack

The TP4100 IC typically comes in a compact package with the following pinout:

1. Power Input: Connect a DC power source (5V to 26V) to the DC jack or directly to the VIN pin. Ensure the power source can supply sufficient current for the charging process.
2. Battery Connection: Connect the positive terminal of the battery to the BAT+ pin and the negative terminal to the BAT- pin.
3. Programming Charging Current: Use a resistor between the PROG pin and ground to set the desired charging current. Refer to the datasheet for the resistor value corresponding to your required current.
4. Status Monitoring: Connect an LED (with a current-limiting resistor) to the STAT pin to monitor the charging status:
   • LED ON: Charging in progress.
   • LED OFF: Charging complete or no battery connected.
5. Enable/Disable: Use the EN pin to enable or disable the IC. Pull the pin high to enable and low to disable.

• Heat Dissipation: Ensure proper heat dissipation, especially when charging at high currents. Use a heatsink or place the IC on a PCB with good thermal management.
• Battery Compatibility: Verify that the battery's voltage and chemistry are compatible with the TP4100's charging profile.
• Input Voltage: Avoid exceeding the maximum input voltage of 26V to prevent damage to the IC.
• Safety: Always include a fuse or other protection mechanism in the circuit to prevent overcurrent conditions.

The TP4100 can be used to charge a battery that powers an Arduino UNO. Below is an example of how to monitor the charging status using the STAT pin:

// TP4100 Charging Status Monitoring with Arduino UNO

const int statPin = 2; // Connect the STAT pin of TP4100 to digital pin 2
const int ledPin = 13; // Built-in LED on Arduino UNO

void setup() {
  pinMode(statPin, INPUT); // Set STAT pin as input
  pinMode(ledPin, OUTPUT); // Set LED pin as output
  digitalWrite(ledPin, LOW); // Turn off LED initially
  Serial.begin(9600); // Initialize serial communication
}

void loop() {
  int chargingStatus = digitalRead(statPin); // Read the STAT pin

  if (chargingStatus == LOW) {
    // STAT pin LOW indicates charging in progress
    digitalWrite(ledPin, HIGH); // Turn on LED
    Serial.println("Battery is charging...");
  } else {
    // STAT pin HIGH indicates charging complete or no battery
    digitalWrite(ledPin, LOW); // Turn off LED
    Serial.println("Charging complete or no battery connected.");
  }

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

1. IC Overheating

   • Cause: High charging current or insufficient heat dissipation.
   • Solution: Reduce the charging current by adjusting the resistor on the PROG pin. Improve heat dissipation with a heatsink or better PCB design.

2. Battery Not Charging

   • Cause: Incorrect battery connection or incompatible battery.
   • Solution: Verify the battery connections and ensure the battery's voltage and chemistry are supported.

3. STAT Pin Not Responding

   • Cause: Faulty connection or damaged IC.
   • Solution: Check the wiring to the STAT pin. Replace the IC if necessary.

4. No Output Voltage

   • Cause: Disabled IC or insufficient input voltage.
   • Solution: Ensure the EN pin is pulled high and the input voltage is within the specified range.

• Can the TP4100 charge multiple batteries in series? No, the TP4100 is designed for single-cell batteries. For multi-cell configurations, use a dedicated multi-cell charger IC.

• What happens if the input voltage exceeds 26V? Exceeding 26V can permanently damage the IC. Always use a regulated power supply within the specified range.

• Can I use the TP4100 without a DC jack? Yes, you can connect the input voltage directly to the VIN pin if a DC jack is not required.

• How do I calculate the resistor value for the PROG pin? Refer to the TP4100 datasheet for the formula and resistor values corresponding to the desired charging current.