How to Use BQ24022 (DRC-10): Examples, Pinouts, and Specs

The BQ24022 is a highly integrated Li-Ion battery charger with power path management, designed and manufactured by Texas Instruments. This component is ideal for portable applications requiring efficient battery charging and seamless power management. It features a built-in high-efficiency switching regulator, supports both USB and AC adapter inputs, and includes advanced safety features such as thermal regulation, overvoltage protection, and battery temperature monitoring.

• Smartphones and tablets
• Wearable devices
• Portable medical equipment
• Power banks
• Handheld gaming devices

The BQ24022 is available in a DRC-10 package with the following pinout:

1. Power Input: Connect the input power source (USB or AC adapter) to the IN pin. Ensure the input voltage is within the range of 4.35 V to 16 V.
2. Battery Connection: Connect the positive terminal of the Li-Ion battery to the BAT pin and the negative terminal to GND.
3. Load Connection: Connect the system load to the OUT pin. The BQ24022 will manage power distribution between the battery and the load.
4. Charge Current Programming: Use a resistor on the ISET pin to set the desired charge current. Refer to the datasheet for the resistor value calculation.
5. Battery Temperature Monitoring: Connect an NTC thermistor to the TS pin for battery temperature sensing. This ensures safe charging under various temperature conditions.
6. Status Indicators: Use the STAT1 and STAT2 pins to monitor the charging status. These pins can drive LEDs for visual indication.
7. Power Good Indicator: Use the PG pin to monitor the validity of the input power source.

• Ensure proper decoupling capacitors are placed near the IN and OUT pins to minimize noise and improve stability.
• Use a low-ESR capacitor on the BAT pin to stabilize the battery voltage.
• Avoid exceeding the maximum input voltage (16 V) to prevent damage to the device.
• If not using the TS pin, connect it to a fixed voltage as specified in the datasheet to disable temperature monitoring.
• Ensure proper thermal management by placing the device on a PCB with adequate copper area for heat dissipation.

The BQ24022 can be used to power an Arduino UNO while charging a Li-Ion battery. Below is an example code to monitor the charging status using the STAT1 and STAT2 pins.

// Arduino UNO example to monitor BQ24022 charging status

const int STAT1_PIN = 2; // Connect STAT1 to digital pin 2
const int STAT2_PIN = 3; // Connect STAT2 to digital pin 3

void setup() {
  pinMode(STAT1_PIN, INPUT); // Set STAT1 as input
  pinMode(STAT2_PIN, INPUT); // Set STAT2 as input
  Serial.begin(9600);        // Initialize serial communication
}

void loop() {
  int stat1 = digitalRead(STAT1_PIN); // Read STAT1 pin
  int stat2 = digitalRead(STAT2_PIN); // Read STAT2 pin

  if (stat1 == LOW && stat2 == HIGH) {
    Serial.println("Charging in progress...");
  } else if (stat1 == HIGH && stat2 == LOW) {
    Serial.println("Charge complete.");
  } else if (stat1 == HIGH && stat2 == HIGH) {
    Serial.println("No battery connected or fault condition.");
  } else {
    Serial.println("Unknown status.");
  }

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

1. Device Overheating

   • Cause: Insufficient thermal dissipation.
   • Solution: Increase the copper area on the PCB around the device for better heat dissipation.

2. Battery Not Charging

   • Cause: Incorrect resistor value on the ISET pin.
   • Solution: Verify the resistor value and ensure it matches the desired charge current.

3. Power Good Indicator Not Active

   • Cause: Input voltage is out of range or unstable.
   • Solution: Check the input power source and ensure it is within the specified range (4.35 V to 16 V).

4. Fault Condition Indicated

   • Cause: Battery temperature out of range or overvoltage condition.
   • Solution: Verify the connection to the TS pin and ensure the battery voltage is within the safe range.

Q1: Can the BQ24022 charge other types of batteries?
A1: No, the BQ24022 is specifically designed for single-cell Li-Ion or Li-Polymer batteries.

Q2: What happens if the input power is removed?
A2: The BQ24022 seamlessly switches to battery power to supply the load via the OUT pin.

Q3: Can I disable charging while still powering the load?
A3: Yes, you can disable charging by pulling the CE pin high while the load remains powered through the OUT pin.

Q4: How do I calculate the resistor value for the ISET pin?
A4: Refer to the formula in the datasheet: R_ISET = 1000 / I_CHG, where I_CHG is the desired charge current in amperes.