Lpc2000

A quick rule of thumb for a 4 layer PCB, is to use the inner layers for 
power and ground planes.  Don't route any signals on the inner layers, 
keeping the planes as connected as possible.  If you have multiple power 
buses, you may be able to split the power plane, but be careful about 
routing signals on the adjacent layer that cross the gap between the 
planes.  This goes the same for the ground plane; avoid routing signals 
across a gap in the plane.  These last two rules are more important at 
frequencies higher than you're likely to encounter on an LPC, but it's 
good to get into the habit, and certainly doesn't hurt (and you'll have 
fewer bad habits to unlearn when you start playing with gigabit Ethernet ;-)

Hope that helps...

--DLM

fredrikssonjohan wrote:

> Hi!
>
> Well, this is off topic from LPC's but here we go...
>
> As my boards get more and more crowded I want to look at 4 layer PCBs
> instead of my usual 2 layer ones. What I can't find is some good info
> and tutorials of best practice and what you shall think of designing
> a 4 layer card.
>
> I guess (and hope) that some here in the group does 4 layer cards and
> can point me somewhere or give a tip or two :-)
>
> Looking forward to any input on the subject!
>
> Cheers
> /Johan