This low cost low voltage 3W class-D stereo amplifier is based on PAM8403 IC, The PAM8403 is a 3W, class-D audio amplifier. It offers low THD+N, allowing it to achieve high-quality sound reproduction. The new filter-less architecture allows the device to drive the speaker directly, requiring no low-pass output filters, thus saving system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8403 is much better than that of Class-AB cousins. It can extend the battery life, which makes it well-suited for portable applications. Trimmer Potentiometer helps to adjust the volume control, CN1 provided to feed the audio signal, CN2 power supply, Mute and shutdown in, LS1 and LS2 to connect the speaker. Shutdown and Mute pin required high level signal input, and can be connect to VDD power pins for normal operation, can be connect to GND for shutdown or mute the audio. The amplifier works well with standard audio signal input.
Low Cost/Voltage 3W Class-D Stereo Audio Amplifier for Portable Gadgets – [Link]