I am trying to understand the SGMII Driver and Receiver DC specification. Here is the link to SGMII specification - SGMII.pdf I am studying.

  1. Table-1: Driver DC specification

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  1. Table-2: Receiver DC specification

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  1. Waveform created from above tables (table 1 and 2)

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Q1: Can you please varify the waveform created from the tables (table 1 and 2)?

Q2: Why the single ended Vpp (1050 mV) of the Receiver side is more than Driver sigle ended Vpp (650 mV)?


1 Answer 1


On Q1: What you've shown for the driver is just one case, the one where Voh is at it's max and Vol is at it's minimum, which will never occur at the same time. The 650 mV output differential voltage you show from that case is greater than the max output differential voltage specification of 400 mV.

Again, just considering the driver, some combinations of the worst case (best case?) values listed in that table cannot occur at the same time. For example, you can't have a driver output where Voh=1525 mV and Vout(diff)=150 mV, because would mean the output offset voltage is 1450 mV, which exceeds the spec for output offset voltage.

On Q2: That's just telling you that the receiver can tolerate 200 mV higher or 200 mV lower voltages than what the driver can put out.

  • \$\begingroup\$ On Q2 response: so that receiver can accommodate overshoot and undershoot from the driver? \$\endgroup\$
    – student7
    May 9, 2022 at 1:39
  • 1
    \$\begingroup\$ That's the way I understand that. Unless there's something else in the data sheet that says otherwise. \$\endgroup\$
    – SteveSh
    May 9, 2022 at 12:04

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