The Adafruit STEMMA Audio Amp is a super small mono amplifier that 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, it's 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!
This board is a simplified version of our breadboard-friendly Adafruit Mono 2.5W Class D Audio Amplifier board. This version is designed to be 'plug and play' - with no soldering required. You can input the audio via the JST-PH 3 Pin connector - such as a pin header cable or one with alligator clips. The trade-off is that this board doesn't have differential inputs, instead, the audio inputs are referenced to the power/signal ground wire.
The input to the amplifier goes through 1.0uF capacitors so you can have DC. The output is "Bridge Tied" - which means the output pins connect directly to the speaker pins, with no connection to the 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 to another amplifier, it should drive the speakers directly.
Comes with a fully assembled and tested breakout board. We also include a header to plug it into a breadboard and a 3.5mm screw-terminal block so you can easily attach/detach your speaker. You will be ready to rock in 15 minutes! The speaker is not included, use any 4 ohms 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.