What if there is no idle pattern output from ADIN2111?

Hi cweom 

What you're seeing are the autonegotiation signals. These signals should be present on both ports unless the port is in software power down (SWPD) mode or there is potential damage to the boards.

Can you confirm whether the SWPD dip switch is set to not be in SWPD mode? 

Regards,

Shazia

I checked the SWPD dip switch and the mode is set.

However, while debugging, I think the cause came from a strange place.

When I measured the waveform directly at pins 4 and 5 of ADIN2111, there was a DC level, but there was no swing of the auto-negotiation signal.

However, when I removed 74930000 and bypassed it, the auto-negotiation signal was measured at pins 4 and 5.

It's strange that the output waveform of ADIN2111 is not measured due to the transformer.

If the PCB I made myself had the same problem, I would suspect the circuit or layout, but the problems are different for each.

Is there any related data on the influence of the transformer and ADIN2111?

Hi cweom 

Thank you for sharing your schematic.

It may be that during the assembly of the board, the pads of the transformer were not soldered correctly. We have seen this happen before. Could you please check the solder joints on the transformer pads and ensure they are properly connected?

Regards,

Shazia