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SN74AVC4T245: SN74AVC4T245 Absolute Input Voltage Range

Jade Goo
Intellectual 1940 points

Part Number: SN74AVC4T245

Hi Team,

SN74AVC4T245 absolute input voltage range in datasheet is below :

Input voltage range, VI (see Note 1): I/O ports (A port) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 4.6 V

NOTES: 1. The input voltage and output negative-voltage ratings may be exceeded if the input and output current ratings are observed.


Refer NOTE 1, absoulte input voltage range could be expanded depend on current.
Would you let me know more detailed current range with expanded input voltage range?
Thank you.

Best Regards,
Jade

  • 0
    TI__Guru 64010 points
    Hi Jade,

    The same abs max rating table list the input clamp and output clamp current ratings.
    I would like to know why the abs max input voltage range is being considered? the device should be operated in within the ROC, and the overshoots and undershoots may exist which must be limited within the abs max ratings.
  • 0 in reply to ShreyasRao
    TI__Intellectual 1940 points
    Hi Shreyas,

    Yes. Customer normal operation under recommned operating range.
    This is abnomal situation that connect/disconnect another board that path connected with SN74AVC4T245.
    I know SN74AVC4T245 didn't support hot swap, but this is abnormal case and they want to know our device will damaged or not.
    Thank you.

    Best Regards,
    Jade
  • 0 in reply to Jade Goo
    TI__Guru 64010 points
    Hi Jade,

    Yes, you are correct. Hot swap is not guaranteed with the SN74AVC4T245 device. It supports level 1 isolation ( Ioff partial power down mode).
    As long as the abnormal case do not exceed the ROC of the datasheet, the device will not be damaged and within the Abs max conditions, there will not be reliability concerns. beyond the abs max conditions, the device may have long term reliability damage or concerns.
  • 0 in reply to ShreyasRao
    TI__Intellectual 1940 points
    Hi Shreyas,

    One more question.
    Is there any spec about transiant duration?
    For example, other device mentioned about overshoot/undershoot transiant duration like as below.
    ex. Overshoot and undershoot of -2V to (VIHMAX + 2) volts is permitted for a duration of <20ns.
    As you mentioned before, "overshoots and undershoots may exist which must be limited within the abs max ratings.".
    It looks like even if transiant duration, overshoot and undershoot must under abs max ratings -0.5V ~ 4.6V, but I want to double check with you.
    For now, customer -1V transiant duration under 10ns.
    Thank you.

    Best Regards,
    Jade
  • 0 in reply to Jade Goo
    TI__Guru 64010 points
    Hi Jade,

    If its not mentioned explicitly in the datasheet, then it cannot be guaranteed. The likelyhood of device damage may be limited for the short duration transient, however, as per the datasheet, it is violating the abs max spec.
    Is there a possibilty to change the schematic to include a series resistor to limit the undershoot to within -0.5V?