4 or 6 layers

[robertferanec]

I agree with goncaloc, I would use at least 1 layer dedicated to solid GND plane. If you would not have 1 solid GND plane you can run into many problems.

This video may help you: https://youtu.be/vALt6Sd9vlY

[goncaloc]

You will always be better/safer with a dedicated GND plane.
Also, and specially you having a analog top and a digital bottom you will want as much separation/shielding as you can between the two.

[mulfycrowh]

But I don't like to split planes even they are power supplies planes!

[mulfycrowh]

Hi everyone,

I have a design involving 2 power supplies.
I made it using 4 layers.
I have components on top and bottom layers.
I used top layer for analog part.
I used layer 2 for both power supplies and signals because I get enough place to do so. I cannot use a smaller board.
I used layer 3 for signals.
I used bottom layer for digital part with MCU.

Is there any advantage to improve the design with 6 layers involving 2 planes, one both power supplies and the other one for GND.
Thanks for your thoughts.