gEDA-user: QFP fan-out tips

[Andy Peters]

On Oct 6, 2007, at 6:37 AM, Randall Nortman wrote:

> On Sat, Oct 06, 2007 at 07:21:22AM -0400, Bob Paddock wrote:
>>
>>> I route power inwards under the chip, with vias to the power  
>>> planes and
>>> the decoupling cap on the other side.
>>
>> Sometimes doing that adds enough inductance to cause problems,
>> in high frequency boards.
>
> What does "high frequency" mean?  I'm in the <50MHz range.

It's not the frequency that's important, it's the rise time of the  
signals.

-a