https://learn.adafruit.com/adafruit-pam8302-mono-2-5w-class-d-audio-amplifier
Overview | Adafruit PAM8302 - Mono 2.5W Class D Audio Amplifier | Adafruit Learning System
This mono amplifier is able to deliver up to 2.5 Watts into 4-8 ohm impedance speakers. Inside the miniature chip is a class D (very efficient) controller,...