Power throug traces not throug planes

[Paul van Avesaath]

so i was just curious about your thought on this.

i was told today that having power planes is counter productive and cause more harm in analog designs.
from what i understand having a long power trace (lets say 5V) running over a board with ferride beads at each device is better than a power plane. the reason was mentioned that you wil have control on where your return paths are. and you will not bring in noise from other parts of the board..

my gut thells me that this is not correct (i have always done it with planes) but then again that was 99% high speed digital design and not analog. we are talking here about DC voltages so i am curious if there are some analog experts out there that agree with the above statement.

thanks!

[robertferanec]

Your question is specifically about analogue design, right? I am curious to know what other people think about this (I am not expert for sensitive analogue design).

[Paul van Avesaath]

yeah its an inductive sensor.. still find it pretty wierd to use one think long trace on the toplayer for power though it ends up beeing a sort of plane anyway.. .. it just does not make sence to me.. i know for signal paths the return current flows underneath the traces..but how about a 5V power line.. does it comply to that too?

[qdrives]

use one think long trace on the toplayer

How about designing a 3 phase motor drive for 25A. I need 3x 15mm traces, even on 2oz (70um) copper to keep the temperature rise to about 20C.
I always routed power, but I am not heavy on analog either.