Supported ethernet PHY options

I am going to respin some of my boards to use native ethernet instead of the ENC28.

I had a quick look at the schematics for the sitcore SOMs and noticed they all use the DP83848 PHY.
Are there more PHYs that are supported? I am mostly interested in the DP83825I for it’s small form factor and simplicity.

It is on the list https://github.com/ghi-electronics/TinyCLR-Libraries/issues/917 so we would be happy to help you find/use an alternative, at no cost to you! DP83825I can be a good option. All you have to do is send us a board with SITCore and DP83825I and leave the rest to us!

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At the current timeframe, I can’t take you on your offer… So I will put the DP83848 on my board.
I will send you a sitcore board with the DP83825I some other time!

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Is this a external oscillator of some sort? Do you have some specs or a part number for me to use?
Would there be harm in connecting the OE to ground with a pulldown and no connection to an IO pin?

Here is the part.

https://www.digikey.com/en/products/detail/cts-frequency-controls/632L3I050M00000/1648434

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no harm but you need for lower power

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I am currently scouting ideas for a new project and this project would benefit greatly from an onboard ethernet switch.

I am currently looking at this part for the job. But I can imagine it is not supported?

Out of curiosity, what makes it that one PHY is supported and the other is not? To me it seems like any PHY supporting RMII would work :slight_smile:

I added a network switch on this board: It boots up!

I used capacitor coupling to connect the Sitcor module ethernet output to the switch IC. (https://www.ti.com/lit/an/snla088a/snla088a.pdf)

I am in the process of mocking up a SITCore board with https://www.microchip.com/wwwproducts/en/LAN8742A which will be sent to GHI for testing.

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That seems like the perfect solution for me, 3 ports outwards and 1 to the sitcore!!
What is the part number of the ethernet switch IC?

I prefer to use magnetics because isolation is very important in my application.

That sounds good. Can I take one of these boards as well? Would like to test that IC out once it is supported :slight_smile:

What form factor and goodies do you want on it?

@LucaP, I used: https://www.microchip.com/wwwproducts/en/KSZ8795
Now that I am getting back to this project the part looks like it has 0 stock available. I did the initial prototype last year and built 1 board. I have to make some changes to the board then hopefully it will be ready for production.

The capacitor coupling does allow for isolation on the board if necessary. However, you still have the transformer isolation on the 3 exposed ports.
One benefit of having the switch is that you can do cable diagnostics on each port which can tell you if the cable is open or shorted, as well as the length of the cable.
I will be researching adding Single Pair ethernet port to the currently unused MII/RMII port. Not sure yet if it is possible.

Thank you!

I will probably use the KSZ8784
If I connect my SC20100 to the KSZ8794 trough the RMII interface, I have the same amount of ethernet ports going outwards as you have currently. It saves me from having a PHY and the 8794 is available at the moment.

The cable diagnostics feature sounds very useful :slight_smile:

Formfactor is not so important for me here, I will probably only use the board for development purposes on my desk. For goodies I’d like a (isolated) can transceiver, one of these for MAC address purposes and then a lot of gpio broken out to connect things to on a breadboard. Maybe even some gadgeteer sockets?

OK, leave it with me…might need to go cap in hand to GHI to get some more SC20100’s…

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