20W Audio Amplifier LM1875

LM1875 is an old yet reliable Audio amplifier IC. It is very common and you can get it for very cheap price. With this IC you can get up to 30W power output with 33V supply using 8 ohms speaker.

It has very simple circuit and very easy to build because it requires few components. This design is for single supply application. You can find more information about this IC on its Datasheet on this link.

PCB Design

This time around I am playing with Kicad. It’s is very different from what I used to but it has more feature and best of all its free! The layout is not yet optimized(i.e. size of the trace) because i am still learning. But you can download the project file so you can edit it for your own project. The size of the capacitors are just assumed.

3D render

The best about Kicad is that it has built-in 3D rendering feature for your board at no cost. This is a very useful tool for visualizing your project.

Downloads

You can download the Kicad project here:



Download page