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TUSB320LAI: VDD Supply

Shmuel Davis
Expert 2920 points
Part Number: TUSB320LAI
Other Parts Discussed in Thread: TUSB320, TUSB322, TUSB322I

Can I power the TUSB320LAI VDD with VBUS if I am using a TPD1S514-1 to protect the supply ?

In the data sheet for the TUSB320LAI it states Recommended VDD Supply voltage range : 5 Max, however in Fig. 20 it states "Optional power TUSB320 with VBUS less than 5.5V" and the Absolute Max Raing fro VDD = 6V. 

The TPD1S514-1 has a VBUS_SYS ramp = 23.5mS, Vovp = 5.99V max and Tovp = 100nS ! 

  • 0
    TI__Genius 16150 points
    Hi Shmuel,

    The TUSB320 can be powered by VBUS<5.5V. Although VBUS supply must be below of this parameter to ensure the proper operation of he device. The absolute maximum rating is a value only for temporal conditions, not for permanent operating conditions. If the device is supplied with a value close to 6V, the performance cannot be guaranteed, even it could be damaged.

    Best Regards,
    Luis Omar Moran
    High Speed Interface
    SWAT Team
  • 0 in reply to Luis Omar Moran
    TI__Expert 4325 points

    Another option is TUSB321A or TUSB322 which are designed to be powered via VBUS as they can support VDD up to 5.5V. TUSB320 is rated only to 5V.

    Regards,
    Brian

  • 0 in reply to Brian Quach
    Expert 2920 points
    The TPD1S514-1 appears to guarantee that the part being protected will see 5.99V for ~100ns before the discharge circuit reduces the voltage below 5V. Do you think this is enough ?
  • 0 in reply to Shmuel Davis
    TI__Genius 16150 points

    Shmuel,

    As Brian mentioned the TUSB320LAI was rated at 5V. Despite the discharge circuit reduces the voltage below 5V, the condition of 5.99V ~100ns could affect the device. Hence, TI cannot guarantee the proper performance in this condition. Please take a look in another options.

    Thanks,

    Luis

  • 0 in reply to Brian Quach
    Expert 2920 points
    Dear Brian,

    Thanks for your suggestion. The problem is that :-

    TUSB321A doesn't have industrial temperatures
    Our application is UFP, GPIO ONLY thus I can't use TUSB322I (which has Device Only – UFP/Sink (I2C Mode only))

    It is a shame since we don't need the enable and we only need GPIO so TUSB321A would be perfect if it was in the right temperature range (why is it that TI didn't make this option - most chips I have come across do offer the at least the industrial temp. option ???)

    Best regards

    Shmuel
  • 0 in reply to Luis Omar Moran
    Expert 2920 points
    Dear Luis,

    I do have +5 to +3.3V regulator in my system - thus I could power the VDD of the TUSB320LA with this +3.3V.

    If I do so this will mean that my VBUS_DET will be powered along with the CC lines before the VDD power supply. Is there any problems with this power sequencing ?

    Thank you once again for all your help

    Best regards

    Shmuel
  • 0 in reply to Shmuel Davis
    TI__Genius 16150 points
    Hi Shmuel,

    Since this device supports dead battery mode, the sequence is not critical. The restriction is to meet the requirements of VDD.

    Regards,
    Luis