On 26/05/2011 09:39, V G wrote:
> Wow, okay. Thicker power/ground tracks it is. What thickness/clearance do
> you recommend?

For ground, all the unused space

For power 0.1" if possible.

It's not just resistance but inductance and the fact a 1/4 wavelength is=20
good transmitting aerial, hence decoupling close to chip.

if 10MHz signal has about 1nS rise time or better that could be 1GHz or=20
higher harmonics. That's 15cm for a 1/4 wave.

The Power and ground of IC can have nano second spikes when turning on=20
/off the FET on the relay as it's rapidly charging/discharging the FET=20
gate capacitor. Some designs with long traces put 50 Ohm to 220 Ohm at=20
CPU and at Gate end of trace to reduce rise time and also for the FET=20
reduce likelyhood of self oscillation or nearby radio switching it.

--=20
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