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DP83867CS: About the SGMII DC Specification

user6236094
Intellectual 320 points
Part Number: DP83867CS


Hi,Team

I am looking for DC and UI specification, or Mask for the DP83867CS SGMII.
I found the answer in the thread below.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/921602/dp83867is-dp83867is-dp83867is-sgmii-dc-specification 

Please tell us more about the above SGMII DC specs.

[Question 1]
Is the Output VOD (differential-peak) above the Differential Amplitude (VOD) shown below?


[Question 2]
The above Diffrencial threshold is MIN: -100mV, MAX: 100mV, does VIDIFF=200mV or more necessary?


[Question 3]
In the data sheet of DP83867, there was a description of 1.25Gbps LVDS Differential signal.
DP83867CS, is the device compliant with the LVDS specification below?

◇LVDS standard
・Differncial voltage(VOD) = 247～454[mV]
・Offset Voltage(Vos)　 　 = 1.125～1.375[V]
・Diffrencial threshold(Vth) = MIN:-100[mv]、MAX：100[mV]
・Input voltage range(Vin)　 = 0～2.4[V]

  • 0
    TI__Genius 14006 points

    Hi User,

    user6236094 said:

    [Question 1]
    Is the Output VOD (differential-peak) above the Differential Amplitude (VOD) shown below?

    Yes.

    user6236094 said:

    The above Diffrencial threshold is MIN: -100mV, MAX: 100mV, does VIDIFF=200mV or more necessary?

    It is a minimum of 100mV difference, not 200 mV.

    user6236094 said:
    [Question 3]
    In the data sheet of DP83867, there was a description of 1.25Gbps LVDS Differential signal.
    DP83867CS, is the device compliant with the LVDS specification below?

    Yes, it can be compliant to these specs. 

    Best regards,

    Melissa

  • 0 in reply to Melissa Chang
    Intellectual 320 points

    HI, Melissa

    Thank you for answering.
    Please let me know the following additional points.

    ＞It is a minimum of 100mV difference, not 200 mV.
    　Which of the following is the differential threshold (Vth) of the DP83867CS?
    　・Differential threshold (Vth) = MIN: -100[mV], MAX: 100[mV]
    　・Differential threshold (Vth) = MIN: -50[mV], MAX: 50[mV] 

    ＞[Question 3]
    ＞Yes, it can be compliant to these specs.

    In the LVDS specification, Differential voltage(VOD) is 247～454[mV].
    However, the DP83867CS Differential voltage (VOD) is 150～400[mV].
    I think it does not comply with the LVDS specification, am I correct?

  • 0 in reply to user6236094
    TI__Mastermind 40555 points

    Hello,

    The US offices are closed 7/4/23 for Fourth of July holiday. Melissa will respond to your post upon her return 7/5/23.

    Sincerely,

    Gerome

  • +1 in reply to user6236094
    TI__Genius 14006 points

    Hi User,

    user6236094 said:
    ＞It is a minimum of 100mV difference, not 200 mV.
    　Which of the following is the differential threshold (Vth) of the DP83867CS?
    　・Differential threshold (Vth) = MIN: -100[mV], MAX: 100[mV]
    　・Differential threshold (Vth) = MIN: -50[mV], MAX: 50[mV] 

    It is a Differential threshold (Vth) = MIN: -50[mV], MAX: 50[mV].

    user6236094 said:

    ＞[Question 3]
    ＞Yes, it can be compliant to these specs.

    In the LVDS specification, Differential voltage(VOD) is 247～454[mV].
    However, the DP83867CS Differential voltage (VOD) is 150～400[mV].
    I think it does not comply with the LVDS specification, am I correct?

    By definition, SGMII has more lenient DC parameters so it does not comply with LVDS strictly.

    All this information can be found in the specification, you can find it by googling 'Cisco Serial-GMII Specification Revision 1.8'

    Best regards,

    Melissa