• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 3 answers
  • Subscribers 33 subscribers
  • Views 907 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS125MB203: Cross switch/Buffer on 10Gbps SFI interface consultation

user5290333
Prodigy 40 points
Part Number: DS125MB203
Other Parts Discussed in Thread: DS100MB201, , DS100MB203

Dear TI Engineers:

We need a 1:2 switch or fan-out buffer using on 10G SFP transceiver.

We find 3 TI chips as candidates, DS125MB203, DS100MB203, DS100MB201.

Questions as below:

1) The speed on board can reach 10.3125Gbps. Considering performance/cost and supply, which device is recommended?

2) The PHY interface we use is SFI Interface, but no explicit description about SFI in datasheet's application. So We need confirm.

Thank you! 

  • 0
    TI__Mastermind 43795 points

    Hi,

    I would use either the DS100MB203 or the DS125MB203. 

    In an SFP transceiver application I would place the MB203 approximately 2 inches from the connector.

    Regards,

    Lee

  • 0 in reply to Lee Sledjeski
    Prodigy 40 points

    Thank you for reply！

    Some questions about DS100MB201：

    1）Can it support SFI interface？

    2）If we do not want SMBUS for management, can we use Pin Mode？

    3）The power VDD is only 2.5V？3.3V is not supported？

  • 0 in reply to user5290333
    TI__Mastermind 43795 points

    Hi,

    I would not recommend the DS100MB201 for 10 Gbps operation - the MB203 products work better.

    All of these parts can use either pin mode or an SMBus mode of operation.

    The DS100MB201 does only support 2.5V VDD.

    Regards,

    Lee

  • 0 in reply to Lee Sledjeski
    Prodigy 40 points

    OK, i will follow your advice, but need some guidance in using MB203:

    1) In SFI interface application, the MODE pin21# should be connected to WHERE?

    2) In Pin Mode, How to config EQ[1:0] and DEM[1:0]? From datasheet, is it based on FR-4 thickness and Trace width?

  • 0 in reply to user5290333
    TI__Mastermind 43795 points

    Hi,

    For SFI MODE = Low (1K resistor to GND)

    The equalization and de-emphasis settings will be determined by several variables.

    For equalization it is important to know the channel attenuation on the input side of the MB203 and if any Tx equalization will be applied to the incoming signal.  I recommend to start with a low setting and work up in equalization to find the optimum value.

    For de-emphasis I would recommend to use a setting between 0 and -3.5 dB if possible.  The optimal placement for most SFI or SFP+ applications is approximately 2 inches or 5 cm away from the connector.

    If you are using pin mode, I recommend to place both PU and PD resistors into the schematic for these signals.  This will allow for more flexible setting options.

    Regards,

    Lee