Hello Muhammad,

Unless you are customer premises equipment, you should only have to meet
the intrabuilding surge requirements of GR-1089 (typically metallic
ethernet interfaces are not intended as outside plant lines).  Using the
RJ-45 with integrated magnetics should be an acceptable configuration as
long as you are comfortable that the internal wiring can handle the
differential mode surge current (verify from supplier).  Most of them
advertise at least 1500V isolation, so they should not have a problem
with the common mode surge.  Why are you concerned about placing the
surge protection behind the transformer?  In differential mode, the
integrated transformer (1:1?) and magnetics should attenuate the maximum
amplitude transferred to the secondary side somewhat and the surge
protection can handle any that happens to make it into the secondary,
thereby protecting your chip.  I know Semtech makes a device especially
for 100BaseT, but not sure about 1000BT.

Muhammad Sagarwala wrote:

> Hello Gurus,
>
> I am new to this list so pardon me if my questions sound naive.
>
> The question I had was, for nebs compliance we need to pass power
> cross and lightening tests.  For boards with copper ports (100baseT
> and 100base T), is it possible to use rj45 connectors with integrated
> magnetics and still get pass these tests. Has anybody done that - if
> yes, is it possible to share the method.  I believe there are
> components (e.g. sedactors) one can use, but
>
> those are capacitve and might impact the signal integrity.  Also,
> mostly that kind of stuff is used on the line side of the
> transformer.  I am just a little bit hesistant to put in on the
> secondary side...
>
> Any input would be highly appreciated...
>
> Thanks
>
> Muhammad

--
Regards,

Scott Lemon
CASPIAN NETWORKS
RTP, NC
Ph:(919) 547-1078
Fx: (919) 547-1010
[email protected]
www.caspiannetworks.com

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