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TUSB8041: Requirement for external oscillator

Oba
Genius 17705 points

Part Number: TUSB8041
Other Parts Discussed in Thread: TUSB2036,

Hello,

I would like to confirm some specification for XI input when external clock oscillator is used.

  1. This pin requires 1.8V, but there is no specification about VIL_max and VIH_min.
  2. Acceptable duty range
  3. Rising time and Falling time (10-90%)
  4. Max Input current
  5. Max Input capacitance
  6. Is any delay required from oscillator output stable to GRST high ?

Regards,
Oba

  • 0
    TI__Guru 60870 points

    Hello Oba,

    1.  Standard +/- 10 % range on 1.8V can be assumed ( 1.62V / 1.98V)

    2.  45% - 55%

    3.  5 ns 

    4.  n/a

    5. 0.4 pF nominal

    6.  Yes, clock must be stable before the end of reset.  

    Regards,

    JMMN

  • 0 in reply to JMMN
    TI__Genius 17705 points

    Hello,

    Thanks for your answer.

    >1.  Standard +/- 10 % range on 1.8V can be assumed ( 1.62V / 1.98V)

    I also need VIL_max value. Could you please tell me it?

    >6.  Yes, clock must be stable before the end of reset.  

    TUSB2036 requires that the clock has to be stable 60usec before reset inactive.
    Doesn't TUSB8041 require this kind of time?

    Regards,
    Oba

  • 0 in reply to Oba
    TI__Guru 60870 points

    Hi Oba,

    1.  I misread your original question.   Vil_max is 0.7V and Vih_min is 1.05V.

    6.  Yes, I would recommend at least 100 us of valid clock before the reset completes.

    Regards,

    JMMN