Re: [SI-LIST] : Modeling Package parasitics

Chee Yee Chung ([email protected])
Mon, 16 Feb 98 15:37:00 PST

Text item:

formula for inductance of a round wire, isolated in space (assuming no
L = 0.002*length*(ln(2*length/radius)-0.75)

L = uH
Lenght, radius = cm


______________________________ Reply Separator _________________________________
Subject: [SI-LIST] : Modeling Package parasitics
Author: [email protected] at SMTPGATE
Date: 2/16/98 2:43 PM

Does anybody have an accurate way of modeling package parasitics,
in particular in a QUAD simulation environment. I have been using
a lumped inductance for a BGA & SQFP package but find this to be very
inaccurate with fast edge rates and small voltage level swings. The ringing
from the inductor causes the signal to cross switching thresholds in the
simulation environment, but this ringing is not seen on the lab bench.
My feeling is that a specified ZO, TPD & and Length should be used
for the bonding wire, trace on the BGA package and the pin.
Does anybody have any thoughts on what values I could use for
the bonding wire?

Mark Nass

Text item: External Message Header

The following mail header is for administrative use
and may be ignored unless there are problems.


Precedence: bulk
Sender: [email protected]
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0
Subject: [SI-LIST] : Modeling Package parasitics
From: Mark Nass <[email protected]>
To: [email protected]
Date: Mon, 16 Feb 1998 14:43:08 -0800
X-Mailer: Windows Eudora Pro Version 3.0 (32)
X-Sender: [email protected]
Message-Id: <[email protected]>
Received: from by banshee.rosscc (4.1/SMI-4.1)
id AA21473; Mon, 16 Feb 98 14:45:47 PST
Received: from banshee.rosscc by (SMI-8.6/SMI-4.1)
id OAA12503; Mon, 16 Feb 1998 14:44:10 -0800
Received: from ( [])
by (8.8.7/8.8.7) with SMTP id OAA04985
for <[email protected]>; Mon, 16 Feb 1998 14:43:30 -0800
Received: from ( [])
by (8.8.8/8.8.8) with ESMTP id OAA17931
for <[email protected]>; Mon, 16 Feb 1998 14:43:49 -0800 (PST)
Received: from (saturn.EBay.Sun.COM [])
by Eng.Sun.COM (SMI-8.6/SMI-5.3) with SMTP id OAA15123
for <[email protected]>; Mon, 16 Feb 1998 14:43:49 -0800
Received: from Eng.Sun.COM by (SMI-8.6/SMI-SVR4)
id OAA16407; Mon, 16 Feb 1998 14:45:20 -0800
Errors-To: [email protected]
Received: by (SMI-8.6/SMI-SVR4)
id OAA16411; Mon, 16 Feb 1998 14:45:25 -0800
Received: from (silab.Eng.Sun.COM [])
by Eng.Sun.COM (SMI-8.6/SMI-5.3) with SMTP id OAA12234;
Mon, 16 Feb 1998 14:57:10 -0800
Received: from Eng.Sun.COM (engmail2 []) by mercury.Sun.COM (SMI-8.6
/mail.byaddr) with SMTP id OAA20882; Mon, 16 Feb 1998 14:57:13 -0800
Received: from mercury.Sun.COM (mercury.Sun.COM [])
by (8.8.6/8.8.5) with SMTP id PAA10555
for <[email protected]>; Mon, 16 Feb 1998 15:25:12 -0800 (PS
Received: from ( []) by fmm (8.8.5/8.7.3) with ESMTP id PAA01364 for <[email protected]>; Mon, 16 Feb 1998 15:21:50 -0800 (PST)
Return-Path: [email protected]