Power Planes

[Sebastiaan]

Dear All,

anyone ever considered a 4 or 6 layer amplifier PCB, and design power planes?

The idea is put the output, and power planes on top of each other to reduce magnetic fields.

Pro's and con's?

With kind regards,
Bas

[nigelwright7557]

Its really not needed even with high power amps.

I would use a groundplane tho.

I would otherwise just thicken up power tracks as much as possible to reduce their impedance.

[jcx]

magnetic field radiation/suseptability reduction with multilayer layout could be good, but planes aren't really the appropriate tool at audio frequencies

below MHz currents happily spread out in planes to follow the least resistance path - they will not stay confined in "images" of the traces as in high frequency digital

so you really need to think more of geometrically balanced/common centroid cross section but discrete conductive paths in the layout for the heavy current loops - and consider Class B switching of current draw from + to - rails (maybe interleave/sandwich with the power load/gnd return)

[Sebastiaan]

I think one can archive positive (in case of a multilayer board) to keep the power supply lines and outputs on top of each other. It gives a clean PCB as well, and u can keep the high current separated from the line level stuff.

In that case not really full planes, but thick polygon fill traces.

With kind regards,
Bas