The PAM8403 from Diodes Inc. is a 3W, Class-D Stereo Audio Amplifier. It offers low THD+N, allowing it to achieve high-quality sound reproduction. The new filterless 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 amplifiers. It can extend the battery life, which makes it well-suited for portable applications. Additional to the amplifier hardware, this tiny module carries a Bluetooth 4.0 audio receiver, what turns it into the perfect driver for small stereo bluetooth speakers, or bluetooth headphones. With dimensions of only 25.6 x 42.3 x 7.76 mm and a weight of just about 5g is it one of smallest available Bluetooth stereo amplifier boards today. Bluetooth pairing starts automatically after powering it up. The Bluetooth name this device will show up with is “Blutetooth”. 2 x 3.2 Watt max. Output at 10% THD into 4? load Bluetooth 4.0 enabled Supply Voltage 5V (micro USB) THD+N @ 5V, 1W (4?) <0.15% Quiescent Current ca. 20mA (5V) Signal to Noise 80dB Dynamic Range 90dB Efficiency up to 90% Short Circuit Protection Thermal Shutdown Please note: The actual PCB can have a slightly different layout or different color. But the size, the circuit and the function is always identical.