DP83869HM: Placement of AC coupling capacitors in SGMII interface

Dion Kriel

Part Number: DP83869HM
Other Parts Discussed in Thread: DP83869

I am using a DP83869 as an RGMII to SGMII bridge to connect to an SGMII switch over some inches of trace (switch = broadcom BCM53422).

I believe I need some ac coupling caps in the SGMII lines, but I am not sure where to locate them for best performance?

Closest to transmitter or closest to receiver?

0 Gerome Cacho over 3 years ago

Hi Dion,

I am talking to the team, and hope to get a reply for your question shortly.

Sincerely,

Gerome

0 Gerome Cacho over 3 years ago in reply to Gerome Cacho

Hi Dion,

The best location for the capacitors would be on the transmitter side.

Sincerely,

Gerome

0 Dion Kriel over 3 years ago in reply to Gerome Cacho

Thank you, just a follow-up question... The other side is a Broadcom SGMII switch, and Broadcom wants the caps receiver side.

So it seems I can locate both cap pairs TX and RX on the switch side.

Do you see any issues with that? I am assuming the receiver is the one that is sensitive to the placement? Is that correct?

0 Gerome Cacho over 3 years ago in reply to Dion Kriel

Hi Dion,

I do not see any issues regarding this.

Sincerely,

Gerome

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