@Anonymous wrote:
I am creating a 4 layer board and can only dedicate an internal layer for power. I currently have 2 voltages of 3V, and 5V running into the board and powering various circuits. How can I create a split power plane so that these circuits can run properly?
This is actually quite straightforward. You use two polygons, one for each power rail and assign the polygon ranks such that they automatically get isolated from each other. As an example I will assume your 5V plane is the plane which goes to most things around the board and the 3V is derived from the 5V and goes only to certain areas of the board (doesn't really matter, this is just for an example). What I would do in this case is create a global 5V polygon which covers the entire board and set its rank to 6 (lowest priority). I'd then draw the 3V polygon where it needed to go within the board and set it's priority higher than the 5V polygon (i.e. 5 or lower). The 3V polygon will be isolated from the 5V polygon automatically. You can adjust the clearance between the two by changing the isolation settings of the 3V polygon.
Best Regards,
Rachael
