[SI-LIST] Multiple power planes coupling to ground

Hello all,
If you have multiple power planes sandwiched between 2 ground planes -
somewhere in your stackup - next to each other like so:

|
GND
|
VCC1
|
VCC2
|
VCC3
|
GND
|

From a high-frequency noise filtering/decoupling standpoint, VCC1 and VCC3
have relatively good capacitive coupling to ground, but what about VCC2?

I understand that there will be capacitive coupling between VCC2 and the
other planes, but does this still give me a reasonably good filtering scheme
for VCC2 at high frequency? Or does it just couple VCC2 noise onto my other
power planes?

I'm trying to visualize the loop currents to ground when devices draw power
from VCC2. Will the VCC2 power noise will couple directly through the other
power planes to ground, or will the other power planes will act like shields
so that VCC2 no longer has good low-inductance filtering for high frequency
noise?

Any insight would be appreciated.

Thanks,
Joseph


------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

Other related posts: