Feasibility Request: Using Transformer Coupling Between Intel WGI210AT and BCM53134OKFBG to Resolve

[jiuzhen]

Hello,

We are currently working on a custom switch design using the Intel WGI210AT Ethernet controller connected to the Broadcom BCM53134OKFBG switch chip.

Originally, we used direct capacitive coupling between the two chips. In mass production testing, we found that this topology leads to a **0.2% failure rate of Ethernet ports** under certain operating conditions.

To resolve this issue, we are planning to modify the design to use **transformer coupling** between the WGI210AT and BCM53134OKFBG instead. We would like to request your review and validation of this proposed transformer coupling solution.

Our current formal Intel support ticket (Case ID: 06868896) references the same project, and we are now seeking additional design guidance here.

Could you please confirm:
1. Whether transformer coupling is a supported and recommended topology for connecting the WGI210AT to a third-party switch chip like the BCM53134OKFBG?
2. Any key specifications, design considerations, or recommended reference designs for implementing such a transformer coupling?
3. Whether there are any known limitations or compatibility issues with this approach?

We have attached the revised schematic for your reference. Thank you for your guidance and support.