10/100Mbps Magnetics with 10/100/1000 PHY

Question

I have a SOC that has a KSZ9031RN PHY, that is a Gigabit PHY. But I'm going to use only in 10/100 Mode with 4 wires.

Gigabit PHY datasheet recommends a magnetic for Gigabit Ethernet, that are different from Fast Ethernet magnetics.

Can I use 4 Wire Fast Ethernet magnetic with that Gigabit PHY if I'm going to use it only in 10/100 Mode?

Thanks!

The devil's in the detail and I see none. – Andy aka Aug 28 '19 at 12:57 — Andy aka, Aug 28 '19 at 12:57

score 2 · Answer 1 · answered Aug 28 '19 at 14:18

2

Short answer: Yes you can use the KSZ9031RN with only 10/100 magnetics.

Read the Support datasheet and note section 3.8.

So you will have to program the devices to ensure it does not attempt to size 4-pair as opposed to 2-pair connections.

answered Aug 28 '19 at 14:18

Jack Creasey

1 Answers1