Hi Reid,
A few thoughts on your questions:
1. for high side noise, a low freq. high side PDN model should be
sufficient. This is not to say the high freq. noise on the input rail cannot
appear at the output of the SMPS - by parasitic coupling, the internal path
of the SMPS, they actually could transmit across the SMPS and show up at the
load side. But for a proper load side PDN design the HF noise usually is not
a concern unless the decaps are strikingly insufficiently provisioned, and
the PDN is extremely short in length. Therefore, I would say for a high side
PDN, a freq. range from DC to at most 100MHz might be sufficient. A ferrite
model of this freq. range should not be difficult to obtain I guess?
2. you may try to use Hspice G element to model the constant power.
Regards,
Sherman Shan Chen
SI/PI Group, Kandou Bus
5 Queensbridge, Northampton, UK, NN4 7BF
Office: +44 1604 635826 Email: shan@xxxxxxxxxx
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> On Behalf
Of agathon
Sent: Tuesday, November 26, 2019 9:29 PM
To: si-list <si-list@xxxxxxxxxxxxx>
Subject: [SI-LIST] SMPS buck: behavioral model for high-side current noise
Hello all,
I need to model noise on a high-side plane (feeding several SMPS).
I will extract a plane model but for the freq/time domain simulation...
My 2 challenges I can see are:
1) ferrite SMT model ...
but I see the si-list archive on this. They were nixed on the pcb respin,
anyway, but need to model their usage.
2) behavioral noise source that emulates SMPS constant-pwr current.
I don't need to model a particular part. Vendor models, I'm told, don't
operate at the pwm switching level, anyway.
My sense is that I only need a behavioral model that will act like "constant
power", so it simply switches current in and out and adjusts voltage in lock
step, like a buck SMPS. I'm thinking a pwl file for a current waveform then
a ICVS across it, parametrized to achieve constant power.
Comments? And, if agreed, suggestions on common elements to do this?
Regards,
Reid
------------------------------------------------------------------
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
------------------------------------ KANDOU BUS Confidentiality Notice
-------------------------------------------
The preceding message (including any attachments) contains proprietary
information that may be confidential,
privileged, or constitute non-public information.
It is to be read and used solely by the intended recipient(s) or conveyed only
to the designated recipient(s).
If you are not an intended recipient of this message, please notify the author
or sender immediately by replying
to this message and delete this message (including any attachments hereto)
immediately from your system.
You should not read, retain, disseminate, distribute, copy or use this message
in whole or in part for any purpose,
not disclose all or any part of its content to any other person.
------------------------------------ KANDOU BUS Confidentiality Notice
-------------------------------------------
------------------------------------------------------------------
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
