2 GND planes (Power Switching Supply course)

[nicolas.logioia]

Hello people!

I finished working with the Switching Supply project (the course was very useful!!)

I'd like to know why would you use 2 GND planes on a PCB (this having 6 layers in total, in this case). I could make it more simpler with one plane. Also, manufacturing the board would be very expensive (like 200 bucks in seedstudio, 5 units min., 6 layers). Could I re design the board using 2 layers without getting EMI problems just to make things cheaper?

Thanks!
Nico

[robertferanec]

If you have a look at their reference design, you will notice they have done it on 4 layers (I attached the file). I would probably not go for 2 layer PCB - it could be too noisy and I am not sure about quality of the outputs.

In the course I used 6 layers as I wanted students to practice on a multi-layer PCB (more than 2 layers). Also in many applications you will find the implementation of this power supply done very similar way as is done in the course.