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TCAN1145-Q1: SCK tolerance at 4MHz

Shinji Tsuji
Genius 14209 points
Part Number: TCAN1145-Q1


Tool/software:

Hi team,

I plan to use SPI clock at 4MHz. 

Since fsck is rated 4MHz MAXIMUM and min fsck and fsckh is rated as >125ns, I wonder how to consider clock tolerance above 4Mhz. 

I believe SCK = 4MHz typical should be no problem, correct?

Is there any guideline of the tolerance of this 4MHz clock input?

regards,

  • 0
    TI__Guru 74322 points

    Tsuji-san,

    An engineer has been assigned to this thread and will respond by end of business 03/14/2025.

    Regards,

    Eric Hackett 

  • 0
    TI__Mastermind 28990 points

    Hi Shinji,

    From the characteristics data I see we do have some tolerance >4Mhz, however 4Mhz is the max clock rate we guarantee that SPI can work, customer should not rely on tolerance above it.

    Yes, there will be no problem at SCK = 4 Mhz.

    Regards,

    Sean

  • 0 in reply to Sean Guo
    TI__Genius 14209 points

    Hi Sean-san,

    Thank you for your reply. 

    I understand the device is designed to handle 4MHz SCK (with reasonable tolerance) and no critical issue 

    (e.g. setup/hold time violation) even if this clock drift like 5-10%. 

    Is my understanding correct?

    regards,

  • 0 in reply to Shinji Tsuji
    TI__Mastermind 28990 points

    Hi Shinji-san,

    Yes this is correct. We do have some tolerance from our testing results, but we don't guarantee SPI will work stably above 4Mhz (from a datasheet specification perspective, it is a violation). In real application, it is safe to assume that working at 4Mhz won't cause any issue.

    Regards,

    Sean