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SN74LV4T125: Relative propagation delay variation between channels and temperature drift

Takuma Ito
Expert 5200 points
Part Number: SN74LV4T125


Hello, Could you tell me relative propagation delay variation between channels? 
I want to minimize the delay difference between channels. There is propagation delay spec in the datasheet, but this is part to part variation. I want to know channel to channel variation within single ICs. could you provide any data for that?

in addition, could you tell me temperature drift of propagation delay?  is this different between channels? 

  • 0
    TI__Genius 16735 points

    Hello,

    The difference in delay between the individual channels on an individual part  is referred to as channel-to-channel skew or output skew. This is not covered as a datasheet parameter.

    However we have a guarantee for all of our logic devices to limit output skew to 1ns. Keep in mind that this applies to a single unit with all driving inputs connected together and the outputs switching in the same direction while driving identical specified loads.

    Here is the what to expect for typical max skew based on technology. These are not guaranteed though:

     - TTL = 800ps
     - Bicmos  = 500ps
     - CMOS is 250ps

    AVC and LVC devices are CMOS
    SN74LV4T125 is a low-voltage CMOS buffer gate

    Thanks!
    -Karan

  • 0 in reply to Karan Kotadia
    TI__Expert 5200 points

    hello Karan,
    Thank you for your answer. 


    Could you tell me about temperature drift as well? 
    How the propagation delay changes depending on the temperature?
    increase or decrease? do you have any data? 
    Also the channel to channel skew will change by temperature change, or not much? 

  • 0 in reply to Takuma Ito
    TI__Genius 16735 points

    Hi,

    So the propagation delays listed in the datasheet are spec'd over all operating temperature range. This means those are the maximum values and the actual propagation delay should be within those values.

    We do not collect data on the propagation delay over the temperature and so cannot guarantee but propagation delay should increase with temperature. However it will never cross the values listed in the datasheet.

    Channel to channel skew should not change with temperature as the channels will all shift over temperature equally since they are made at the same time with the same process.

    Thanks!
    -Karan