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LTC4381 as an eFuse

Category: Hardware
Product Number: LTC4381


I want to use the LTC4381 as an eFuse (due to part shortage...) and I wonder if someone at ADI could confirm that I can use it safely the way I plan to.

The voltage I want to protect is 5V (permanent) , so I need to power the IC to a higher voltage (that's what I understand from  the spec).

So I want to connect Vcc independently like this drawing:

Is it a valid connection?

Thanks for confirming.

  • Hi jricard,

    The datasheet mentions that IN pin should be connected to the supply input which I believe is the Vcc.

    I would suggest to verify your design using LTspice.

  • Thanks Ron,

    The simulation works down to 2.5V at both supply inputs (out of spec), so I don't believe the model is accurate enough to confirm. That is why I was asking for technical feedback from ADI.

    I understand that the typical connection is both pins at supply input,  but if the supply to protect is 5V nominal, what is the correct connection? My understanding of the internal schematic is that it might work the way it is drawn in my initial email, otherwise Note 7 at page 4 prevents using the IC with the typical connection with a 5V supply input nominal (even though if you look only in the table without checking the notes, it would seem to work).

    Thanks for helping,


  • The datasheet also mentions "The VCC pin can also be powered separately from the VIN pin." and also VCC is 4V MIN. VCC is where the charge pump is being operated. I think the idea will work. Please verify in bench.