This super small mono amplifier is surprisingly powerful - able to deliver up to 2.5 Watts into 4-8 ohm impedance speakers. Inside the miniature chip is a class D controller, able to run from 2.0V-5.5VDC. Since the amp is a class D, its very efficient (over 90% efficient when driving an 8Ω speaker at over half a Watt) - making it perfect for portable and battery-powered projects. It has built in thermal and over-current protection but we could barely tell it got hot. There's even a volume trim pot so you can adjust the volume on the board down from the default 24dB gain. This board is a welcome upgrade to basic "LM386" amps!

The A+ and A- inputs of the amplifier go through 1.0uF capacitors, so they are fully 'differential' - if you don't have differential outputs, simply tie the Audio- pin  to ground. The output is "Bridge Tied" - that means the output pins connect directly to the speaker pins, no connection to ground. The output is a high frequency 250KHz square wave PWM that is then 'averaged out' by the speaker coil - the high frequencies are not heard. All the above means that you can't connect the output into another amplifier, it should drive the speakers directly.

Comes with a fully assembled and tested breakout board. We also include header to plug it into a breadboard and a 3.5mm screw-terminal blocks so you can easily attach/detach your speaker. You will be ready to rock in 15 minutes! Speaker is not included, use any 4 ohm or greater impedance speaker.

  • Output Power: 2.5W at 4Ω, 10% THD, 1.5W at 8Ω, 10% THD, with 5.5V Supply
  • 50dB PSRR at 1KHz
  • Filterless design, with ferrite bead + capacitors on output.
  • Fixed 24dB gain, onboard trim potentiometer for adjusting input volume.
  • Thermal and short-circuit/over-current protection
  • Low current draw: 4mA quiescent and 0.5mA in shutdown (due to pullup resistor on SD pin)

Note: The terminal block included with your product may be blue or black.

Power Pins

  • VIN - This is the power pin. To power the board, give it 2.0V-5.5VDC.
  • GND - This is common ground for power.

Input Pins

  • A+ and A- - Audio inputs for the amplifier. Signal goes through 1.0uF capacitors, so they are fully 'differential'. If you don't have differential outputs, simply tie the A- to ground. 

Shutdown Pin

  • SD - The shutdown pin. Can be used to power down the amplifier by tying to ground.

Output Pins

  • + and - - Amplifier output pins. They are spaced to allow for a terminal block to be soldered in place. The output is "Bridge Tied" so that the output connects directly to the speaker pins, no connection to ground. 

This guide was first published on Jun 03, 2022. It was last updated on Mar 08, 2024.