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DS16F95QML: Device Failure during power shut down

Shinu.V.Mathew
Genius 10560 points
Part Number: DS16F95QML

Hi Team,

Our customer is using DS16F95QML-V device for one of the application. During normal operation, the device is wired in a card which is powered from a standard power supply. Last day, there was a power failure to the card and after that the device is not working normally. All other devices in the board are working correctly.

The device is configured with fail-safe mode. The AND voltage with respect to Ground is around 4V (High) and 1V (Low). After the power failure, the output voltage levels of AND reduced to 2.2V (High) and 1.25V (Low). However the NAND voltages are remain the same before and after.

What may be the reason for this failure. Please help with thoughts to analyse this issue.

Thanks in advance for your help and support.

Regards, Shinu Mathew.

  • 0
    TI__Guru 62930 points
    Shinu,
    Can you please elaborate on what you are referring to with "AND" and "NAND" voltages? The device has A, and B outputs. Is this what you are referring to?
    What failsafe configuration are you referring to? Please provide a schematic for clarity.

    Is it possible a voltage surge was present that exceeded the abs max ratings when the power supply failed?

    Regards,
    Wade
  • 0 in reply to Wade Vonbergen
    TI__Genius 10560 points
    Hi Wade,
    Sorry for the confusion. 'AND' is 'Out A' and 'NAND' is 'Out B'.
    If Vcc exceeds max abs ratings, can it degrade the output voltage levels.
    We measured the pin impedance, the impedance are 1.17 MOhm from outA pin to +5Vcc and 1.13 MOhm from outA pin to GND. The outB pin impedances are in KOhms.

    Regards, Shinu Mathew.
  • 0 in reply to Shinu.V.Mathew
    TI__Guru 62930 points
    Shinu,
    I seems apparent that the device has been damaged.
    Exceeding VCC abs max ratings will stress the device and it conceivable that it could damage one or both output transistors.

    If this answers your question, please click "Verify it as the answer"
    Regards,
    Wade