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TUSB2036: Requirement for XTAL1 input when using external oscillator

Oba
Genius 15750 points
Part Number: TUSB2036

Hello,

I want to confirm some specification for XTAL1 input when 48MHz external oscillator is used.

  1. I would like to know Input capacitance value on this pin
  2. Is input current the same as I_IL and IIH, +- 1uA?
  3. I would like to know acceptable frequency tolerance for 48MHz.
  4. I would like to know acceptable duty.
  5. I would like to know rising time and falling time (10-90%)
  6. I would like to know acceptable jitter.

Regards,
Oba

  • 0
    TI__Guru 60865 points

    Hi Oba,

    1.  It can be assumed to be a few pF.

    2. n/a

    3. 50 ppm is recommended

    4.  45-55%

    5. 2.5 ns nominal

    6. The clock must meet the USB 2.0 full-speed jitter specification as outlined in Table 7-9 of the  USB 2.0 specification (available at www.usb.org/.../). The source jitter tolerance TDJ1 has to be between –3.5 ns (min) to 3.5 ns (max). TDJ2 has to be between –4 ns to 4 ns.

    Please post if you have difficulty finding a device that meets all requirements and we can review the datasheet of the oscillator.

    Regards,

    JMMN