How to Use LD2461: Examples, Pinouts, and Specs

The LD2461 is a low-dropout (LDO) linear voltage regulator designed to deliver a stable and precise output voltage with a minimal input-to-output voltage difference. This makes it an ideal choice for applications where power efficiency and compact design are critical. The LD2461 is particularly well-suited for battery-powered devices, portable electronics, and low-noise analog circuits.

• Battery-powered devices (e.g., smartphones, wearables)
• Portable electronics
• Low-noise analog circuits
• Microcontroller power supplies
• IoT devices and sensors

The LD2461 is designed to operate efficiently in a variety of environments. Below are its key technical specifications:

The LD2461 is available in multiple package types. Below is the pin configuration for the SOT-223 package:

1. Input Capacitor: Connect a capacitor (typically 1 µF to 10 µF) between the VIN pin and ground to stabilize the input voltage and reduce noise.
2. Output Capacitor: Connect a low-ESR capacitor (typically 1 µF to 10 µF) between the VOUT pin and ground to ensure stable operation and minimize output voltage ripple.
3. Load Connection: Connect the load to the VOUT pin. Ensure the load does not exceed the maximum output current of 500 mA.
4. Thermal Management: If using the SOT-223 package, connect the thermal pad to a large ground plane to improve heat dissipation.

• Input Voltage: Ensure the input voltage is at least 0.3V higher than the desired output voltage to maintain proper regulation.
• Capacitor Selection: Use low-ESR capacitors for both input and output to ensure stability.
• Thermal Dissipation: For high-current applications, ensure adequate heat sinking or airflow to prevent overheating.
• Reverse Polarity Protection: Add a diode in series with the input to protect the LD2461 from reverse polarity damage.

The LD2461 can be used to power an Arduino UNO by providing a stable 5V output. Below is an example circuit and code:

1. Connect the VIN pin of the LD2461 to a 9V battery.
2. Connect the GND pin to the ground of the Arduino UNO and the battery.
3. Connect the VOUT pin to the 5V pin of the Arduino UNO.

// Example code to blink an LED using an Arduino UNO powered by the LD2461
// Ensure the LD2461 provides a stable 5V output to the Arduino's 5V pin.

const int ledPin = 13; // Pin connected to the onboard LED

void setup() {
  pinMode(ledPin, OUTPUT); // Set the LED pin as an output
}

void loop() {
  digitalWrite(ledPin, HIGH); // Turn the LED on
  delay(1000);                // Wait for 1 second
  digitalWrite(ledPin, LOW);  // Turn the LED off
  delay(1000);                // Wait for 1 second
}

1. Output Voltage is Unstable or Incorrect

   • Cause: Insufficient input or output capacitance.
   • Solution: Ensure proper capacitors (low-ESR, 1 µF to 10 µF) are connected to the VIN and VOUT pins.

2. Excessive Heat Generation

   • Cause: High input-output voltage difference or insufficient heat dissipation.
   • Solution: Use a heat sink or improve airflow around the component. Reduce the input voltage if possible.

3. No Output Voltage

   • Cause: Incorrect wiring or damaged component.
   • Solution: Verify all connections and ensure the input voltage is within the specified range.

4. Component Fails Under Load

   • Cause: Load exceeds the maximum output current of 500 mA.
   • Solution: Reduce the load or use a higher-current regulator.

Q1: Can the LD2461 be used with a 3.3V microcontroller?
A1: Yes, the LD2461 can provide a stable 3.3V output if configured correctly. Ensure the input voltage is at least 3.6V to maintain proper regulation.

Q2: What happens if I exceed the maximum input voltage?
A2: Exceeding the maximum input voltage (16V) can damage the LD2461. Always ensure the input voltage is within the specified range.

Q3: Can I use the LD2461 without an output capacitor?
A3: No, an output capacitor is required for stable operation. Use a low-ESR capacitor with a value between 1 µF and 10 µF.

Q4: How do I calculate the power dissipation of the LD2461?
A4: Power dissipation can be calculated as ( P = (V_{IN} - V_{OUT}) \times I_{OUT} ). Ensure the component's thermal limits are not exceeded.