Hi Ralph,
Super-quick response - hopefully gives you a little more food for thought.
DC solvers nowadays have the capability to run thermal/electrical co-sim in an
automated iterative loop. This accounts for the change in resistivity of the
conductors, due to heat. The result as I'm sure you well know, is more
resistive loss, which again creates more heat-energy dissipated into PCB.
After a few iterations of the DC solver with the thermal solver, it reaches a
converged state and you get a much more accurate result for IR Drop and the
resistance of the power and ground planes.
You are quite right to point out that 3D-EM solvers typically simulate at a
near-DC frequency.. and then extrapolate to DC.
At first glance I may suggest that a DC solver is the right way to look at your
problem.
Except there is a lingering question for me, about whether or not your problem
is truly DC? What is happening at the sinks (at the ICs) that are drawing the
current? Are they switching? Do you have dynamically changing current draw?
The answer will take you down a different path - and you may need to use both a
DC solver and an FEM engine to give you different perspectives on the same
design.
Best regards,
Stephen.
Stephen Slater
Keysight PathWave Software Solutions
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> On Behalf Of
Ralph Wilson
Sent: Thursday, May 7, 2020 4:11 PM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] 3D Field solvers for DC analysis
[EXTERNAL]
All,
We're looking at some high current power applications where milli-ohms can make
a difference in heat, voltage loss, system performance, etc. Since we're trying
to split hairs (let's ignore for this discussion how accurate the model itself
may be) we've been considering different approaches to the simulation. We, of
course, have DC solvers in hand, but there has also been suggestions about
using 3D field solvers.
I have this gut level distrust of these 3D field solvers at DC - is this
distrust warranted?
Are the field solvers out there accurate at DC? My experience with them has
previously been restricted to S-parameter generation for vias, connectors, etc.
where we're worried
about the high frequency effects. Most of these S-parameters have a low
frequency cut-off.
I think this is where my distrust comes from.
So, the bottom line question is, are 3D field solvers (generally, or any in
particular) accurate at DC? And, (really the same question) is it worth
pursuing 3D modeling/3D simulations for a high current power application?
Thanks!
Ralph Wilson
------------------------------------------------------------------
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:
https://urldefense.com/v3/__//www.freelists.org/webpage/si-list__;!!I5pVk4LIGAfnvw!0zlCV98dSrh0eJFaa4Yc0Cey2De6BhOM4FlBCrFUcnRn3siNAxBdIWRk9Z8Cl3o$
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
https://urldefense.com/v3/__http://tech.groups.yahoo.com/group/si-list__;!!I5pVk4LIGAfnvw!0zlCV98dSrh0eJFaa4Yc0Cey2De6BhOM4FlBCrFUcnRn3siNAxBdIWRkOaIU2zQ$
List archives are viewable at:
https://urldefense.com/v3/__//www.freelists.org/archives/si-list__;!!I5pVk4LIGAfnvw!0zlCV98dSrh0eJFaa4Yc0Cey2De6BhOM4FlBCrFUcnRn3siNAxBdIWRkZgam9zI$
Old (prior to June 6, 2001) list archives are viewable at:
https://urldefense.com/v3/__http://www.qsl.net/wb6tpu__;!!I5pVk4LIGAfnvw!0zlCV98dSrh0eJFaa4Yc0Cey2De6BhOM4FlBCrFUcnRn3siNAxBdIWRkLb0ye8E$
------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
