[802.3af] RE: Surge test with 0.3u/50u
- To: "'Roger Karam'" <rkaram@xxxxxxxxx>, Yair Darshan <YairD@xxxxxxxxxxxxxx>
- Subject: [802.3af] RE: Surge test with 0.3u/50u
- From: Yair Darshan <YairD@xxxxxxxxxxxxxx>
- Date: Wed, 29 Jan 2003 19:24:23 +0200
- Cc: "'Geoff Thompson'" <gthompso@xxxxxxxxxxxxxxxxxx>, "'mike_s_mccormack@xxxxxxxxxxx'" <mike_s_mccormack@xxxxxxxxxxx>, "'Steve Carlson'" <scarlson@xxxxxxxxxxxxx>, "'Schwartz, Peter'" <Peter.Schwartz@xxxxxxxxxx>, "'Dave Dwelley'" <ddwelley@xxxxxxxxxx>, "'Chris DiMinico'" <cd@xxxxxxxxxxxxxx>, "'ccullin@xxxxxxxxx'" <ccullin@xxxxxxxxx>, "David Pincu (Dudi)" <Davidp@xxxxxxxxxxxxxx>, "'stds-802-3-pwrviamdi@xxxxxxxx'" <stds-802-3-pwrviamdi@xxxxxxxx>
- Sender: owner-stds-802-3-pwrviamdi@xxxxxxxxxxxxxxxxxx
not run a test with 0.3u/50u 1KV through two 404 ohms in
run a test with 1.2u/50u 1KV - 4KV through 2ohms to 12ohms and in some
tests I pass without external protection
some tests I failed without external protection (bad luck for PCB and its
inhabitants...). all of these tests were part of immunity tests and not part of
tested only the behavior from 2ohm to 12 ohm at 1.2u rise time and saw
significant difference at this range alone (2ohms 12ohms).
Increasing the source impedance from 2-12 ohms to 202 ohms improve the outcome
dramatically which is not a big surprise.. Ip max
Regarding the equipment required: I am
checking with labs around here for 0.3us rise time generator.
I don't know personally of somebody who pass
this tests (0.3u , 404ohms) usually it is implementation and layout dependent
and above all, it is done at system level not at chip or module
I assume that there are many that pass this
test due to the fact that it is old requirement in 802.3 and now that I have
notice in drawing 33-18 that the source impedance is 202 ohm I believe that it
was not a big challenge.
If you are doing surge tests as part of
immunity tests 1K-2KV, 1.2u/50us through 2-12 ohms as part of EMI package
(required only for environment B)
than meeting : 1K, 0.3u/50u, through 202
ohms is much easier and you are OK for 802.3.
IN ANY CASE YOU SHOULD TEST IT IN LAB DUE
TOO SENSITIVITY OF THE RESULTS TO LAYOUT AND IMPLEMENTATION.
Roger Karam [mailto:rkaram@xxxxxxxxx]
Sent: Wednesday, January 29,
2003 6:44 PM
To: Yair Darshan
Cc: 'Geoff Thompson';
'mike_s_mccormack@xxxxxxxxxxx'; 'Steve Carlson'; 'Schwartz, Peter'; 'Dave
Dwelley'; 'Chris DiMinico'; 'ccullin@xxxxxxxxx'; David Pincu (Dudi);
Subject: Re: Surge test with 0.3u/50u
did you or anyone
else do this test?
did you pass it?
and where can we find the equipment
to test this.
At 08:31 AM 1/29/2003, Yair Darshan
Chris, Roger and
We in Vancouver wanted to
delete the requirement of 0.3u/50u 1000V fault tolerance
I have also mentioned that this is a
It is true if it is done with low
source impedance 2-12 ohms which is the standard surge test when it forms
part of the immunity tests during EMI tests.
However, this requirement is specified by figure 33-18 with two 404
ohms source resistance which make life much easier.
So if we can easily remove this requirement from the draft lets do
If it cause to much trouble (old requirement from
802.3) than it doesn't worth the time, I don't believe we will have problems
with 1KV pulse 0.3u/50us
through 202 ohm source
resistance (two 404 ohms in parallel according to figure 33-18).
The above info was sent to Chad as part of
my comments to draft 4.01 as informative material to Roger and others who
had concerns regarding this issue.
Darshan Yair Chief Engineer PowerDsine
Ltd. - Powering Converged Networks 1 Hanagar St., P.O. Box
7220 Neve Ne'eman Industrial Zone Hod Hasharon 45421, Israel Tel:
+972-9-775-5100, Cell: +972-54-893019 Fax:
+972-9-775-5111 E-mail: <mailto:yaird@xxxxxxxxxxxxxx>. <http://www.powerdsine.com>