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TPS2115A: ABS MAX ratings of reverse current

K.Yaita
Guru 29690 points
Part Number: TPS2115A

Hi Team,

Is it possible case to damage TPS2115ADRB if applying 5V to OUT under Q1=ON and IN1=3V condition?




I think reverse current from OUT(5V) to IN1(3V) is occured in this case and would like to know ABS MAX ratings of reverse current.
Is the value 2.5A (ABS MAX of continuous output, Tj<105℃)?

Best Regards,
Yaita / Japan disty

  • 0
    Guru 29690 points

    May I have your comments?

    Best Regards,
    Yaita

  • 0 in reply to K.Yaita
    TI__Genius 10370 points

    Hi K. Yaita,

    I'm moving this question to the appropriate forum so that one of our engineers can answer your question as quickly as possible.

    Best Regards,
    Aramis P. Alvarez

  • 0
    TI__Genius 15710 points

    Hi K. Yaita,

    The datasheet states that "an integrated comparator prevents turnon of a FET switch if the output voltage is greater than the input voltage." Therefore, Q1 would not turn on if IN1=3V and OUT=5V. Q1 would stay off until OUT dropped to 3V.

    Thanks,

    Alek Kaknevicius

  • 0 in reply to Aleksandras_Kaknevicius
    Guru 29690 points

    Hi Alek-san,

    Thank you for your reply.
    I understood Q1 is off under IN1=3V and OUT=5V condition.
    However I would like to ask if TPS2115A could be damaged in the following sequence. 

    1) apply 3V to IN1 under D1=1, D0=0 (Q1 FET is ON)
    2) apply 5V to OUT

    I think reverse current is occured instantaneously in this case, so it is the background for asking ABS MAX ratings of reverse current.

    Best Regards,
    Yaita / Japan disty

  • 0 in reply to K.Yaita
    TI__Genius 15710 points

    Hi Yaita,

    Thank you for the clarification. In this case, yes, there would be reverse current. As stated in the datasheet:

    When the TPS211x switches from a higher-voltage supply to a lower-voltage supply, current can potentially flow back from the load capacitor into the lower-voltage supply. To minimize such reverse conduction, the TPS211x does not connect a supply to the output until the output voltage has fallen to within 100 mV of the supply voltage. Once a supply has been connected to the output, it remains connected regardless of output voltage.

    Because the MOSFET is bidirectional, the maximum current through the device should be the same whether it is forwards or backwards. In the case of the TPS2115A, this is 1.5A or 2.5A depending on the package.

    Out of curiosity, what kind of application is this, and why is there a voltage present on the output of the device?

    Thanks,

    Alek Kaknevicius

  • 0 in reply to Aleksandras_Kaknevicius
    Guru 29690 points

    Hi Alek-san,

    Thank you for your support.
    I understood "Once a supply has been connected to the output, it remains connected regardless of output voltage" and external reverse current blocking schottky diode is required in this case.

    >Out of curiosity, what kind of application is this, and why is there a voltage present on the output of the device?
    I couldn't hear the application but my customer considers ORing function using two TPS2115As.

    Best Regards,
    Yaita