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SN74LVC1G14: SN74LVC1G14 datasheet spec check

Frank Xiao
Genius 12055 points
Part Number: SN74LVC1G14
Other Parts Discussed in Thread: SN74LVC1G34,

Hi team,

My customer is designing the SN74LVC1G14DCKR now. The datasheet says: for 3.3v application. tpd is 1.5~4.6ns.

We want to check whether the spec has connection with the temperature and frequency. If my customer check one device the spec is 2.7ns. Whether the other devices can be 1.5~4.6ns, or just around 2.7ns.

Thanks.

BR

Frank

  • 0
    TI__Guru* 96752 points
    Hi Frank,
    The propagation delay of a particular device will change from process variation and temperature (not frequency).

    TI can only guarantee that the propagation delay will remain within the datasheet specified values under the given conditions. It is recommended to design systems based on the worst case values - ie, if your system is timing sensitive and operates at 3.3V, be sure that it will work for both 1.5ns and 4.6ns of delay.
  • 0 in reply to Emrys Maier
    TI__Genius 12055 points
    Hi Emrys,

    My customer use the chip to delay the 125Mhz clock. Do you have some other devices has smaller variation about the delay time?

    Thanks.

    BR
    Frank
  • 0 in reply to Emrys Maier
    TI__Genius 12055 points
    Hi Emrys,

    Could you please help check my new question? Thanks.
    BR
    Frank
  • 0 in reply to Frank Xiao
    TI__Guru* 96752 points
    Hey Frank,
    There are some devices will smaller ranges - for example, the SN74LVC1G34 lists 1ns to 3.5ns at 3.3V. The datasheet values are valid across process and temperature corners.

    You won't find a device that doesn't have a range, however. Even if a typical value is listed, it doesn't mean that every device will be the same.

    Can you share any application details? Why is the clock delay so critical to their system?
  • 0 in reply to Emrys Maier
    TI__Genius 12055 points
    Hi Emrys,

    I have checked the datasheet, for -40~125°C spec, it's similar as the SN74LVC1G14. Thanks.

    BR
    Frank
  • 0 in reply to Frank Xiao
    TI__Guru* 96752 points
    Hey Frank,
    Just FYI, if the customer needs an extremely accurate delay, a long PCB trace can be used -- approximately 6" per 1ns of required delay if they are using FR4 board material. The exact distance will depend on the velocity of propagation, which in turn is reliant on the board's dielectric constant.

    Vp = c/sqrt(εr) -- for non-magnetic materials (such as copper on FR4)