Building Your Own Discrete DIY Class D Audio Amplifier!

This is one video in my series on PIC Microcontroller Applications

In this video we will learn how to build a Class D amplifier. I present a class D amplifier I worked on and share some tips, tricks and design traps for building your own Class D Audio power amplifier.

This Class D amplifier is around 25 watts and run on a maximum of 20 volts and can work with 4 ohm and 8 ohm loads, and maybe even 2 ohm loads but I didn't test with 2 ohms.

Triangle generation is done by the XR2206 and sine wave audio uses a resistor based stereo to mono summing circuit. The op amps are TL081 used for both the sine wave and the triangle wave.

The class d audio power amplifier uses a PIC16 with complementary waveform generator to modulate both waves and drives two TC4420 ICs into a Bridge Tied Load circuit with dual filter output to the loudspeaker.

This design is very flexible and the extra pins on the PIC16 can be used for temperature sensing, current monitoring and implementing safety features. A smaller pin count device can be used.