WIZnet Developer Forum

W7500P Fiber Optic

I’m very happy to know that WIZnet has integrated a physical MAC (IP101G) that can also communicate Ethernet over Fiber Optic (Fx). WIZnet has combined the best of all world into the W7500P (congrats!).

Are there any application notes, user code example, or schematics supporting Fiber Optic communication with W7500P ?
If not, are there plans to add further support for Fiber Optic applications ?

Also, it would be really nice to have a Fiber Optic development board. This will open up the W7500P product to a whole new world of Industrial Applications.

Thanks !

Hello, rfengr

Thanks for your interests!

Here is the Link for W7500P documents and examples.


Please visit wizwiki.net and enjoy it.

And I have to say that W7500P does not support Fiber Optic.

I don’t know WIZnet has plan for it later. If it will happen, she will notice it.

Thank you


I realize I am showing my ignorance here, but I’d like to know what it means for the W7500P
to “not support Fiber Optic”. How is that different from, say CAT5? I was planning to use
the W7500P connected to one of those plug-in transceiver carriers (SFP connector) that
can accept many different media transceivers. Does fiber optic require some MDIO
conversation with the PHY that the W7500 does not support? Does it require something
special from the PHY that the W7500P does not support?

  • eNick

hello, eNick

Sorry the answer is too late…

Fiber Optic is the high speed cable used to carry light. (https://en.wikipedia.org/wiki/Optical_fiber_cable)

The CAT5 is the one of cable standard and the max speed is 100MHz.

W7500P PHY speed is 10 to 100MHz with CAT5 cable.

Do you have to use Fiber Optic Cable ?

The PHY in W7500P doesn’t support Fiber Optic Cable.

Then, you have to use W7500 and PHY supporting MII interface for W7500.

Geez, that was way over a year ago! Nonetheless, I do appreciate your reply. Since my original message, I have implemented a complete ethernet fiber optic system by directly programming an STM32F427 (ARM Cortex M4) chip’s ethernet interface. I’ve connected the ARM chip to a Micrel (now MicroChip) KSZ8041FTL PHY driving a Planet SFP fiber-optic transceiver. I can shove many thousands of ethernet packets per second with this system, and that’s with just an RMII interface, not MII.

It turns out that there is very little difference between CAT5 and SFP fiber-optic, from the point-of-view of a PHY. The KSZ8041FTL has one pin dedicated to selecting CAT5 versus fiber-optic, and all that does inside the PHY is some very minor
stuff like enabling or disabling a scrambler circuit. I have a connector with RMII signals for the input to the PHY, and another connector (this is a prototype) on the output of the PHY that holds the usual TX+,TX-,RX+.RX- signals. Into this PHY output connector I can plug EITHER a CAT5 Magjack adapter board OR an SFP fiber-optic adapter board, with one extra signal line telling the PHY whether to drive the output as CAT5 or FO.

Yes, I must use fiber-optic, not CAT5. This is an industrial application where the customer demands extreme galvanic isolation as well as long cable runs (CAT5 is only good for 100 meters, while FO is good for kilometers).

I would suggest that the WizNet folks would be smart to incorporate fiber-optic PHY capability the next time they update their line of ethernet chips.

Thanks again for your reply.

E. Nicholas Cupery

Yes you are right.

I check the PHY in W7500P.

It has Fiber mode and if there is Fiber transfer module (like SFP Fiber-optic).

The phy can support Fiber-optic.

But unfortunately, WIZnet does not sell any module with it.

Really thank you for your advice and reply!!

If there are many demands of Fiber-optic, WIZnet will support it!!

And I will suggest it!

Thank you


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