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TMUX136: about using TMUX136 to switch CML & LVPECL

Vera Mao
Expert 5065 points
Part Number: TMUX136

Hi dear supporting team,

customer want to use TMUX136 to switch BTW CML & LVPECL level the detail as below:

1. input to port1.

2. when the input is 10Gsps CML signal,  output from port1 without any matching.

3. when the input is 1Gsps LVpecl signal, output from port2 with 150 ohm Rt at the output to GND at each side. 

if customer could accept the signal loss at 5GHz for CML.  is it ok to use it in this way? (i.e. add Rt after the mux  for the LVEPCL signal, will the Ron/Con affect LVPECL?)

TKS A LOT!

  • 0
    TI__Mastermind 45475 points

    Vera,

    The TMUX136 device is a passive FET switch so it doesn't matter if there are termination resistors on the signal path or not.

    The insertion loss at 5GHz for the TMUX136 is about -2.5 dB.  In theory this should support 10Gbps signal but wouldn't think this would support 10Gsps speed in practice.  I would like to know if this is acceptable your system.

    Low Voltage positive/pseudo Emitter-Coupled Logic (LVPECL) voltage level and Common-Mode Logic (CML) signal voltage range is within the recommended operating conditions of the TMUX136.

    The Ron and Con will have an effect on the LVEPCL signal but since the Ron of the TMUX136 (5.7 ohm) is much lower than the termination resistor it will have minimal impact.  The on-state capacitance of the TMUX136 (1.6pF) will simply slow down the rising an falling edges but will not be significant compared to the large bus and receiver capacitance.  

     

    Thank you,

    Adam

  • 0 in reply to Adam Torma
    TI__Expert 5065 points

    Hi Adam，

    tks for your reply! for TMUX136,do we have AMI model? customer want to use it to do simulation. tks a lot!

  • 0 in reply to Vera Mao
    TI__Mastermind 45475 points

    Vera,

    The models for devices are found on the ti.com product folder under the tools and software tab. What are you wanting to see in the model?  Maybe I can answer your concern.   We do not have IBIS-AMI (Algorithmic Modeling Interface).  Most customers use s-parameter models for signal path performance.

    Thank you,

    Adam

  • 0 in reply to Adam Torma
    TI__Expert 5065 points

    Hi Adam,

    yes, I shared the model to customer, but due to the application is using it in SERDES lane, they still need AMI model for for active signal simulation.  may I know whether there is any process for summiting the model application? and if yes, normally how long it will take? tks a lot!

  • 0 in reply to Vera Mao
    TI__Mastermind 45475 points

    Vera,

    Currently there isn't a process to request a model.  The posting below shows how you can create a model based off of the datasheet parameters. 

    Thank you,

    Adam