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.
The output is «Bridge Tied» – that means the output pins connect directly to the speaker pins, no connection to ground. The A+ and A- inputs of the amplifier go through 1.0uF capacitors, so they are fully ‘differential’ – if you don’t have differential outputs, simply tie the Audio- pin to ground. This board is a welcome upgrade to basic «LM386» amps! There’s even a volume trim pot so you can adjust the volume on the board down from the default 24dB gain. It has built in thermal and over-current but we could barely tell it got hot. Since the amp is a class D, its very efficient (over 90% efficient when driving an 8 speaker at over half a Watt) – making it perfect for portable and battery-powered projects. Inside the miniature chip is a class D controller, able to run from 2.0V-5.5VDC.
This super small mono amplifier is surprisingly powerful – able to deliver up to 2.5 Watts into 4-8 ohm impedance speakers. 2130 Mono 2.5W Class D Audio Amplifier – PAM8302 module Mono 2.5W Class D Audio Amplifier – PAM830
