How to Use MCP73833 (MSOP-10): Examples, Pinouts, and Specs

The MCP73833 is a highly integrated Li-Ion battery charge management controller designed for space-constrained applications. It implements a constant current/constant voltage (CC/CV) charging algorithm, ensuring safe and efficient charging of single-cell Li-Ion or Li-Polymer batteries. The MCP73833 is available in a compact MSOP-10 package, making it ideal for portable devices such as smartphones, wearable electronics, and other battery-powered systems.

• Portable consumer electronics (e.g., smartphones, tablets, and cameras)
• Wearable devices
• Power banks and battery packs
• IoT devices
• Medical instruments

The MCP73833 is housed in a 10-pin MSOP package. Below is the pin configuration and description:

1. Power Supply: Connect a regulated DC power supply (3.75V to 6V) to the VDD pin. Ensure the supply voltage is within the specified range.
2. Battery Connection: Connect the positive terminal of the Li-Ion/Li-Polymer battery to the VBAT pin and the negative terminal to VSS.
3. Programming Charge Current: Use an external resistor on the PROG pin to set the desired charge current. The charge current can be calculated using the formula: [ I_{CHARGE} = \frac{1000}{R_{PROG}} ] where ( R_{PROG} ) is in kΩ and ( I_{CHARGE} ) is in mA.
4. Status Indicators: Connect LEDs to the STAT1 and STAT2 pins (with appropriate current-limiting resistors) to monitor charging status and fault conditions.
5. Thermal Monitoring: Connect a 10kΩ NTC thermistor to the THERM pin for battery temperature monitoring. If not used, connect THERM to VDD.
6. Charge Enable: Use the CE pin to enable or disable charging. Pull the pin low to enable charging or high to disable it.

• Thermal Management: Ensure proper heat dissipation by using a PCB with adequate thermal vias and copper area around the IC.
• Battery Safety: Always use a battery with built-in protection circuitry to prevent overcharging or deep discharge.
• Input Voltage: Avoid exceeding the maximum input voltage of 6V to prevent damage to the IC.

The MCP73833 can be interfaced with an Arduino to monitor the charging status via the STAT1 and STAT2 pins. Below is an example code snippet:

// Define pin connections for STAT1 and STAT2
const int STAT1_PIN = 2; // Connect STAT1 to Arduino digital pin 2
const int STAT2_PIN = 3; // Connect STAT2 to Arduino digital pin 3

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);

  // Configure STAT1 and STAT2 as input pins
  pinMode(STAT1_PIN, INPUT);
  pinMode(STAT2_PIN, INPUT);
}

void loop() {
  // Read the status of STAT1 and STAT2
  int stat1 = digitalRead(STAT1_PIN);
  int stat2 = digitalRead(STAT2_PIN);

  // Interpret the charging status
  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 or fault condition.");
  } else {
    Serial.println("Unknown status.");
  }

  // Add a small delay to avoid flooding the serial monitor
  delay(500);
}

1. No Charging Occurs:

   • Cause: The CE pin is not pulled low.
   • Solution: Ensure the CE pin is connected to ground to enable charging.

2. Overheating of the IC:

   • Cause: Insufficient thermal dissipation.
   • Solution: Improve PCB layout with larger copper areas around the IC and thermal vias.

3. Fault Condition Indicated:

   • Cause: Battery temperature out of range or input voltage too high/low.
   • Solution: Verify the battery temperature and ensure the input voltage is within the specified range.

4. LEDs on STAT1 and STAT2 Not Lighting:

   • Cause: Incorrect resistor values or open connections.
   • Solution: Check the connections and use appropriate current-limiting resistors for the LEDs.

Q1: Can the MCP73833 charge a 2-cell Li-Ion battery?
A1: No, the MCP73833 is designed for single-cell Li-Ion or Li-Polymer batteries only.

Q2: What happens if the input voltage exceeds 6V?
A2: Exceeding 6V can damage the IC. Always use a regulated power supply within the specified range.

Q3: Can I disable the thermal monitoring feature?
A3: Yes, if thermal monitoring is not required, connect the THERM pin to VDD.

Q4: How do I calculate the resistor value for programming the charge current?
A4: Use the formula ( R_{PROG} = \frac{1000}{I_{CHARGE}} ), where ( I_{CHARGE} ) is in mA and ( R_{PROG} ) is in kΩ. For example, for a 500mA charge current, ( R_{PROG} = 2kΩ ).