Hi Joerg,

"Joerg" wrote in message
t...
The distance to C87 isn't so bad since you wrote that this node is now on a
full plane. So it has lots of local capacitance to the ground plane, hoping
they are adjacent. Plus a really low "trace" impedance.

This is all true, but I'd much rather have the capacitor that's supposed to
knock the edges off of those switching spikes snuggled right up next to the
inductor connected with some rather fat traces instead of going through two
smallish vias (inductor to the plane) and then two more (plane back to the
capacitor).

The Vcore net powers a DSP that contains an internal DLL to crank a reference
8MHz up to 100MHz or thereabouts. We've found that the jitter on that DLL's
output is quite sensitive to the output capacitance of this swittcher.
Changing the 47uF output to 10uF will cause the DLL to unlock pretty regularly
(this is a Bad Thing!), and even going to 22uF causes an occasional loss of
lock and noticeably more jitter.

Just fire it up and see how it performs.

We won't be getting stuffed boards back for something like a month, but I'll
let you know how it goes then!

As usual, thanks for your help.

---Joel