How to Use Adafruit PAM8302: Examples, Pinouts, and Specs

The Adafruit PAM8302 is a compact, efficient, class D audio amplifier module designed for driving a single speaker or headphone. It is an ideal choice for adding audio capabilities to your projects without requiring a lot of power or space. The PAM8302 can deliver up to 2 watts of power into a 4-ohm load, making it suitable for a wide range of applications, from portable speakers to sound effects for toys and gadgets.

• DIY portable speakers
• Sound effects for costumes or props
• Audio output for alarm systems
• Educational projects involving sound synthesis
• Adding sound to microcontroller projects

• Supply Voltage: 2.5V to 5.5V
• Output Power: 2W at 4Ω, 10% THD; 1.5W at 4Ω, 1% THD
• Efficiency: Up to 85%
• Quiescent Current: 20mA (typical)
• Shutdown Current: <1µA (typical)

1. Power Supply: Connect the Vin pin to a 2.5V to 5.5V power supply and the GND pin to the ground of your power source.
2. Audio Input: Connect your audio source to the IN+ and IN- pins. For a single-ended input, tie IN- to ground.
3. Speaker Output: Connect a 4-ohm speaker between the OUT+ and OUT- pins.
4. Shutdown Control (Optional): If you wish to control the shutdown feature, connect the SD pin to a digital output on your microcontroller. Drive it low to put the amplifier into shutdown mode.

• Ensure that the power supply does not exceed 5.5V to prevent damage to the amplifier.
• Use a capacitor in series with the input if there is a DC bias from the audio source.
• Avoid shorting the output as it may damage the amplifier.
• When using with a microcontroller like an Arduino, ensure that the I/O pins used for shutdown control are configured correctly.

// Example code to control the Adafruit PAM8302 with an Arduino UNO

const int shutdownPin = 2; // Connect to the SD pin of the PAM8302

void setup() {
  pinMode(shutdownPin, OUTPUT);
  digitalWrite(shutdownPin, HIGH); // Enable the amplifier
}

void loop() {
  // Your audio processing code would go here

  // Example: Shutdown the amplifier for 5 seconds
  digitalWrite(shutdownPin, LOW); // Disable the amplifier
  delay(5000);
  digitalWrite(shutdownPin, HIGH); // Enable the amplifier
  delay(5000);
}

• No Sound: Check the power supply and connections. Ensure the speaker is functional.
• Distorted Sound: Make sure the audio input level is not too high, causing clipping. Also, check for proper power supply voltage.
• Amplifier Overheating: Ensure that the amplifier is not driving a load smaller than 4 ohms and that the supply voltage is within the specified range.

• Verify all connections are secure and correct.
• Use a multimeter to check the power supply voltage.
• If using the shutdown feature, ensure the microcontroller pin is configured correctly and functioning.

Q: Can I use the PAM8302 with a 3.3V system? A: Yes, the PAM8302 can operate with a supply voltage as low as 2.5V.

Q: What is the maximum speaker impedance I can use with the PAM8302? A: The PAM8302 is optimized for 4-ohm speakers, but it can drive higher impedance loads at reduced output power.

Q: Can I use stereo input with this amplifier? A: The PAM8302 is a mono amplifier, so it can only amplify one channel. For stereo input, you would need two modules or a stereo amplifier.

Q: How do I adjust the volume of the output? A: The volume can be controlled by adjusting the input audio signal level. This can be done with a potentiometer or through software if the audio is generated by a microcontroller.

This documentation provides a comprehensive guide to using the Adafruit PAM8302 amplifier module. For further assistance, consult the Adafruit forums or the product's datasheet.