TCAN1145-Q1: SCK tolerance at 4MHz

Shinji Tsuji

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,

over 1 year ago

0 Eric Hackett over 1 year ago

TI__Guru 74372 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 Sean Guo over 1 year ago

TI__Mastermind 30930 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 Shinji Tsuji over 1 year ago in reply to Sean Guo

TI__Genius 14964 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 Sean Guo over 1 year ago in reply to Shinji Tsuji

TI__Mastermind 30930 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

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TCAN1145-Q1: SCK tolerance at 4MHz