rcm6700 ethernet with transformerless

We want to connect the ethernet port on RCM6700 to the switch chip and we want a design without transformer.

We want to connect directly, the RCM6700 ethernet port to one port on switch

Any hardware application?

Also we would need to disable the AUTO-MIDX, how can we do it?


Jose Luis

The RCM6710 and RCM6760 have the transformer and Ethernet jack, but the RCM6700 and RCM6750 do not.

As you can see from the schematic, those modules put TX+/TX- and RX+/RX- on the header. What signals does the switch chip expect?


And the schematic for the development board shows taking those signals directly into an Ethernet jack with integrated magnetics:


To disable auto MDIX, it looks like you can define DMAETH100_PXDR_AMDIX_EN as 0 in your project macros.

Thanks for your answer.

I am going to try explain better!!!

we want to connect two PHY (RCM6700 and other manufacture PHY) without magnetics.

We would like to know if we could connect directly TX+/TX- and RX+/RX- between both PHYs or we would need any passive components (resistors, capacitors, etc)

Jose Luis

I’m not sure if that would work or not. I’d recommend searching elsewhere for a solution. This question on the Electronics StackExchange has some good information, but it doesn’t sound easy: https://electronics.stackexchange.com/q/90330

Any chance you were able to get this working? I am battling this exact issue right now.