HD3SS215: Difficulty laying out RTQ package without using vias

Daniel DeLuca

Part Number: HD3SS215

I'm having the same issues as referenced in this forum post: https://e2e.ti.com/support/interface/f/interface-forum/901484/hd3ss215-problem-while-routing-pcb-following-datasheet

I'm not sure how I can route a PCB without using vias with the RTQ package. We would like to stick with the RTQ package for manufacturing and cost purposes.

over 5 years ago

0 David (ASIC) Liu over 5 years ago

TI__Guru**** 187071 points

Hi,

Would you please accept my friendship request and I can share with you the EVM board file which can be used as a reference?

Thanks

David

0 Daniel DeLuca over 5 years ago in reply to David (ASIC) Liu

Prodigy 240 points

Hi David,

I accepted your request. Thanks!

Dan

0 Daniel DeLuca over 5 years ago in reply to David (ASIC) Liu

Prodigy 240 points

David,

I received the board files, thank you. However I noticed there are a large number of vias being used on the high speed data lines. Everything I've read about designing an HDMI interface says to avoid vias as much as possible. Can you shed some light on that?

Dan

0 David (ASIC) Liu over 5 years ago in reply to Daniel DeLuca

TI__Guru**** 187071 points

Dan

If high speed data lines via is not avoidable, I would keep the via count as low as possible to minimize the discontinuity. I would also use the smallest size possible for signal trace vias and HDMI connector pads as they have less impact on the 100ohm differential impedance.

Depending on your design, you can also swap the lane order as long as the lane order matches with each other at the HD3SS215 input and output.

You can also look at adding a retimer to the HD3SS215 output as a possible solution.

Thanks

David

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HD3SS215: Difficulty laying out RTQ package without using vias