Agilex AC-coupling Caps, IEEE 802.3ck

Question

Looking to design a channel according to IEEE 802.3ck 400GBASE-KR4 specification. The IEEE spec calls out 100nF caps on the Rx lanes. Additionally for Agilex, LVDS is recommended with on-board 100 nF AC-coupling capacitors. For design simplicity, we are looking to put 100nF caps on both the Tx and Rx lanes. This would mean that each differential pair would have a 100nF cap on each side of the channel, effectively reducing the capacitance to 50nF.

Where does the 100nF requirement come from? What risks are associated with use 2, 100nF caps on the same differential pair within a channel (one on Tx side and one on Rx side)?

nazrulnaim_intel · Answer

Hello,Sorry for the delay. Regarding your request, please access through this link below.Link : https://www.intel.com/content/www/us/en/docs/programmable/683393/current/power-distribution-network-design-guidelines.htmlBest regards,Nazrul Naim

nazrulnaim_intel · Answer

Hello,As we do not receive any response from you on the previous question/reply/answer that we have provided. Please login to ‘https://supporttickets.intel.com’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.Best regards,Nazrul Naim

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Agilex AC-coupling Caps, IEEE 802.3ck

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