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LMH0397: power on reset

Toshiro Imi
Expert 7470 points

Part Number: LMH0397

Hello,

Our customer has a questin LMH0397 malfunctional while VIN power on from 1V to 2.5V.

When the customer shut down VIN from 2.5V to 1V then power up to 2.5V again, LMH0397 does not transfer SDI_IO input to OUT0.

Would you help him if LMH0397 does not work correctly in this case.

Best regards,

  • 0
    TI__Guru**** 186611 points

    Hi,

    Why are they powering down to and powering up from 1V? Do they see issue if power up/down from 0V to 2.5V?

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    TI__Expert 7470 points

    Hi

    This is becuase FET placing on VIN power line turned off simply while shut down without VIN pull down circuitry. in this case, VIN seems to keep 1V when LHM0397 shutdown. Eventually the system power up from VIN=1V.

     I do not think any issue was hannepned when he start up from 0V to 2.5V yet, can you tell us if such a power up is acceptable ?
    If not, can you also tell us why ?

    regards,

  • 0 in reply to Toshiro Imi
    TI__Guru**** 186611 points

    Hi,

    So the LMH0397 is not fully powered on or off. If you look at the LMH0397 recommended operating condition, VIN is min of 2.375V and max of 2.625V. So 1V is outside of its recommended operating condition and we do not characterize the LMH0397 at 1V, so the LMH0397 behavior at 1V is not guaranteed.

    Thanks

    David