Re: [Gumstix-users] Magnetics in enternet port

[Nikolay R. <nic...@gm...>]

Actually it will work without magetics, but only for *short* distances.

We did a small custom Gumstix board (with integrated network switch) and
made 2 port with magnetics and one without (not enough space on board).
And the third port work perfectly with two twisted pairs on ~100Mbit/s.


--
Best regards
Rogoshchenkov Nikolay


On Thu, Aug 21, 2014 at 2:16 PM, Larry Martin <La...@gl...> wrote:

> Aydin,
>
> I think you may be missing a basic concept of Ethernet electrical
> design.  Ethernet networks are low impedance, so they need to match to
> high impedance IC chip inputs via inductor networks called "magnetics".
>
> The datasheet you linked is an interesting way to connect two NICs on a
> board, but it does not look to me like it would work on an off-board
> connection.
>
> Here is a typical Ethernet jack with magnetics.  The last page of the
> datasheet shows its internal schematic.
>
>
> http://www.digikey.com/product-search/en?x=9&y=10&lang=en&site=us&keywords=553-2050-ND+
>
> If you remove the magnetics and connect ethernet directly to your chip,
> as you have done, stuff won't work.  You have to select a transformer
> something like this:
>
> http://www.digikey.com/product-detail/en/EX2024FNL/553-2215-ND/4291846
>
> and figure out how to solder it into the holes left behind by your
> original jack with magnetics.
>
> Or maybe pry your old jack apart and solder wires to the original pins.
>
> Any way you go will be a science project.  You might be better off
> buying a bigger case.
>
> Good luck,
> Larry
>
> > Since the case I use won't fit, I need to remove the ethernet port on my
> Tobi.
> > I have an ethernet port ready to use on the case and the inner side will
> be connected to Tobi by cable.
> > It's an IP67 standard ethernet connector, that's why I cannot use the
> stock one in my project.
> > I realized that Tobi's ethernet connector has magnetic filters in it but
> my connecter on the case does not.
> > I didn't think it's a big problem in the beginning but it seems it is.
> > Without the magnetics I couldn't make it work correctly.
> >
> > So, can I use my connector w/o magnetics instead of the one on Tobi?
> > What's your advise?
> > Thanks in advance,
> >
> > Tarik
> > ___________________________________
> >
> > Ayd?n Tar?k Zengin, Ph.D.
>
>
>
> ------------------------------------------------------------------------------
> Slashdot TV.
> Video for Nerds.  Stuff that matters.
> http://tv.slashdot.org/
> _______________________________________________
> gumstix-users mailing list
> gum...@li...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users
>