I have a PCB that has 2 Ethernet ports (tested card). I'm building a test bench that I will connect to my PC, the goal is to test if the 2 ports are working.

The PCB doesn't have Ethernet female connector just pogo pins to touch the ethernet connections, then the connections go to 1 Ethernet female connector that I plug to my PC.

I want to make some switch on the test bench PCB so I can select if I want the port A or the port B of the tested card. The switch would be a +5V/+12V/any required voltage signal.

In other words I want a multiplexing IC where I can select the output Ethernet port.

Quick drawing

What would be an IC or the name of this idea? I can't put a name on this and multiplexing ethernet doesn't show anything.

  • \$\begingroup\$ Which Ethernet and how many lanes? 100M, gigabit? Why there is a need to switch, why can't your PC have several Ethernet ports to test both device ports without switching? \$\endgroup\$
    – Justme
    Commented Mar 10, 2022 at 13:09

1 Answer 1


Something like an ethernet LAN switch?

Such as MAX4890 (10/100/1000 Base-T Ethernet LAN Switch) https://www.maximintegrated.com/en/products/comms/optical-communications/MAX4890.html

enter image description here

  • \$\begingroup\$ The goal I'm reaching is the other way around, would this IC work from 2 to 1 ? Looking at the datasheet it seems able to do so but I'm not sure ? \$\endgroup\$
    – Mat
    Commented Mar 10, 2022 at 13:21
  • \$\begingroup\$ I accepted as the answer cause I'm dumb and can't read a datasheet ;) \$\endgroup\$
    – Mat
    Commented Mar 10, 2022 at 13:37
  • \$\begingroup\$ page 10 "The switches are bidirectional, allowing A_ and B to be configured as either inputs or outputs." :) \$\endgroup\$
    – raaymaan
    Commented Mar 10, 2022 at 13:38
  • 1
    \$\begingroup\$ @Mat For ethernet, what would be the difference between a "2-to-1" or a "1-to-2" switch, anyway? Especially with auto MDI/MDIX, ethernet is perfectly bidirectional and symmetric, there is no such thing as an "input port" or an "output port". \$\endgroup\$
    – dim
    Commented Mar 10, 2022 at 13:44

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