This small mono amplifier is surprisingly powerful - able to deliver up to 2.5 W into 4-8 Ω impedance speakers. Inside the miniature chip is a class D controller, able to run from 2.0 V - 5.5 V DC. Since the amplifier is a class D, it's very efficient making it perfect for portable and battery-powered projects. It has built-in thermal and over-current protection. There's even a volume trim pot so you can adjust the volume on the board down from the default 24 dB gain.
The A+ and A- inputs of the amplifier go through 1.0 µF 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 250 KHz 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.
The amplifier comes with a fully assembled and tested breakout board, a header to plug it into a breadboard and a 3.5 mm screw-terminal blocks so you can easily attach/detach your speaker. Speaker is not included, we recommend using any 4 Ω or greater impedance speaker.
- Output Power: 2.5 W at 4Ω, 10% THD (total harmonic distortion), 1.5 W at 8 Ω, 10% THD, with 5.5 V Supply
- 50 dB PSRR (power supply rejection ratio) at 1 KHz
- Filterless design, with ferrite bead + capacitors on output.
- Fixed 24 dB gain, an onboard trim potentiometer for adjusting input volume.
- Thermal and short-circuit/over-current protection
- Low current draw: 4 mA quiescent and 0.5 mA in shutdown (due to pull-up resistor on SD pin)