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SN74LVC8T245: Question about live insertion capability

Genius 4155 points
Part Number: SN74LVC8T245
Other Parts Discussed in Thread: SN74LVTH244A

Hi,

According to the following thread, it says that any part with Ioff feature (includes the LVC family) will support live insertion.

but I couldn't find any description for live insertion capability in SN74LVC8T245 D/S.

On the other hand,there're some devices which live insertion is clearly described in there D/S (i.e. SN74LVTH244A).

Is there any difference about live insertion capability between the device that have a clear description about live insertion and not?

or can we consider there is no difference about live insertion capability between them?

Sincerely,

Go

  • Hey Go,

    You can consider the live insertion capabilities the same. Some devices have more focus on bus driving applications using back planes for example, and so there's probably more of a highlight on that feature in the datasheet since customers would likely find that feature to be more advantageous. My recommendation is to look at the Electrical characteristics table as that table will always include the Ioff spec if the device supports live insertion.  

  • Hi, Dylan

    Thank you for your comment.

    Can I ask you one more question?

    I understand that Ioff feature prevents the device from damaging by current backflow during powerdown.

    Can the device which support hot insertion also prevent the device from damaging by applied surge voltage to input when doing hot insertion?

    I suppose that placing RC filter at input line is the general approach to prevent damaging noted above, 

    Doesn't the device which support hot insertion need the RC filter at input?

    Sincerely,

    Go

  • Hey GO,

    No this slow down the edge rate of the input signal likely causing it to fail the input transition rate spec. This device doesn't have a clamp diode between the input and VCC to clamp the voltage, so the voltage must not exceed whats listed for Vi in the abs max table or else there could be damage.