In message <003001d0f058$e49a7360$adcf5a20$@westin-emission.no>, dated
Wed, 16 Sep 2015, Amund Westin <am...@westin-emission.no> writes:
don't spread out parallel capacitors
==> but could caps there and there on the pcb prevent the so called
"plane bouncing"?
I mean that if you use parallel capacitors to decouple over a wide
frequency range, put them as close together as possible.
Adding capacitors in random places can increase plane bouncing, by
feeding currents into the plane. Capacitors should be placed close to
devices that pass high currents (even short pulses), so that the current
has a short return path to the device's ground pin, passing through as
little of the plane as possible. Because of trace inductance, the pulse
current comes from the capacitor, not the power supply.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
When I turn my back on the sun, it's to look for a rainbow
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
-
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