How to Use Adafruit LM73100 Ideal Diode Breakout: Examples, Pinouts, and Specs

The Adafruit LM73100 Ideal Diode Breakout (Part ID: 6359) is a compact and efficient breakout board featuring the LM73100 ideal diode controller. This component is designed to minimize voltage drop and power loss in power management applications, making it ideal for efficient power routing and protection. The LM73100 ensures reverse current blocking and provides robust protection against overvoltage and overcurrent conditions.

• Power path management in battery-powered devices
• Reverse polarity protection
• Reducing power loss in high-current applications
• Power supply redundancy and OR-ing circuits
• Solar power systems and energy harvesting

• Input Voltage Range: 2.7V to 42V
• Maximum Continuous Current: Up to 5A (dependent on external MOSFET and thermal conditions)
• Quiescent Current: 0.5mA typical
• Reverse Current Blocking: Yes
• Overvoltage Protection: Adjustable up to 42V
• Undervoltage Lockout (UVLO): Adjustable
• Operating Temperature Range: -40°C to +125°C
• Dimensions: 25mm x 17mm x 4mm (excluding headers)

The Adafruit LM73100 Ideal Diode Breakout has the following pinout:

1. Power Connections:

   • Connect the power source to the VIN pin.
   • Connect the load to the VOUT pin.
   • Ensure the GND pin is connected to the ground of the circuit.

2. Enable the Ideal Diode:

   • Pull the EN pin high to enable the LM73100. If left floating, the diode may not operate.

3. Set Overvoltage and Undervoltage Thresholds:

   • Use resistor dividers on the OV and UV pins to set the desired overvoltage and undervoltage thresholds. Refer to the LM73100 datasheet for calculation formulas.

4. Monitor Faults:

   • Connect the FLT pin to a microcontroller or LED to monitor fault conditions. The pin will go low during a fault.

5. Thermal Considerations:

   • Ensure adequate heat dissipation for the external MOSFET and the breakout board, especially in high-current applications.

The Adafruit LM73100 Ideal Diode Breakout can be used with an Arduino UNO to monitor fault conditions and control the enable pin.

• Connect VIN to a 12V power source.
• Connect VOUT to the load (e.g., a motor or LED strip).
• Connect GND to the Arduino GND.
• Connect the EN pin to a digital pin on the Arduino (e.g., D2).
• Connect the FLT pin to another digital pin on the Arduino (e.g., D3).

// Define pin connections
const int enablePin = 2;  // Pin connected to EN
const int faultPin = 3;   // Pin connected to FLT

void setup() {
  pinMode(enablePin, OUTPUT); // Set EN pin as output
  pinMode(faultPin, INPUT);   // Set FLT pin as input

  // Enable the ideal diode
  digitalWrite(enablePin, HIGH);

  // Start serial communication for fault monitoring
  Serial.begin(9600);
}

void loop() {
  // Check the fault pin status
  int faultStatus = digitalRead(faultPin);

  if (faultStatus == LOW) {
    // Fault detected
    Serial.println("Fault detected! Check overvoltage or undervoltage conditions.");
  } else {
    // No fault
    Serial.println("No faults detected. System operating normally.");
  }

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

• Use appropriately rated external MOSFETs for high-current applications to ensure safe operation.
• Ensure proper resistor divider values for the OV and UV pins to avoid false triggering.
• Add decoupling capacitors near the VIN and VOUT pins to reduce noise and improve stability.
• Avoid exceeding the maximum voltage and current ratings to prevent damage to the component.

1. Can I use this breakout with a 24V power supply?

   • Yes, the LM73100 supports input voltages up to 42V. Ensure your load and external components are rated for 24V operation.

2. What happens if the input voltage drops below the UVLO threshold?

   • The LM73100 will disable the output to protect the load from undervoltage conditions.

3. Can I use this breakout for reverse polarity protection?

   • Yes, the LM73100 provides reverse current blocking, making it suitable for reverse polarity protection.

4. How do I adjust the overvoltage and undervoltage thresholds?

   • Use resistor dividers on the OV and UV pins. Refer to the LM73100 datasheet for detailed calculations.

By following this documentation, you can effectively integrate the Adafruit LM73100 Ideal Diode Breakout into your power management applications.