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TPS25942A: TPS25942A : About Reverse current blocking function

ShengHua Yang
Intellectual 690 points
Part Number: TPS25942A

Dear All:

  We have a test for TPS2594A to protect our application ciurcuit. When the input voltage(using Power Suppry) is -6.0V, the output voltage -0.2 V with very low output current.

We found that there is a big current (almost shortly) in the input circuit and the reverse current is so large. Is it normal for this IC (TPS2594A)?

Best Regards,

ShengHua

  • 0
    TI__Guru** 105361 points
    Hi ShengHua,

    Are you trying to switch negative power rail? Current portfolio of eFuses would not support.
    May I know your system requirements and end equipment.

    Best regards,
    Rakesh
  • 0 in reply to Rakesh
    Intellectual 690 points
    Dear Rakesh:

    I got it. Is there any ICs for protecting in the application circuit and powering off input power source when user switch negative power rail?
    We intend to design a protection circuit and auto switch-off in the power source for any users connecting wrong direction power source.
    In our system, we have a application for door locking control by Blue Tooth interface.

    Thanks your kind support.

    Best Regards,
    ShengHua
  • 0 in reply to ShengHua Yang
    TI__Guru** 105361 points

    Hi ShengHua,

    The following configuration will help protect if user connects power source in reverse direction. Let me know if this suits your need.

    Best Regards,

    Rakesh

  • 0 in reply to Rakesh
    Intellectual 690 points

    Dear Rakesh:

      Thanks your suggestion. It is a good method by to reduce inverse current in the wrong power source.

    We have two considerations for the application circuit. One is lower idle circuit in normal operation; another is inverse protection,when user connects wrong direction power source.

    After adding the protection diode in the reverse direction, the sinking current is larger (Vin/(R1+R2+R3)+Vin/Req) than no protection diode (Vin/Req) in the normal operation.

    How can we have a reverse protection when running inverse power source and no extra operation current in normal mode?

    Best Regards,

    ShengHua

  • 0 in reply to ShengHua Yang
    TI__Guru** 105361 points
    Hi ShengHua,

    what is the sinking (idle) current with and without protection diode?
    I assume, your operating voltage is 6V ?

    Regards
    Rakesh
  • 0 in reply to Rakesh
    Intellectual 690 points
    Dear Rakesh:

    We hope our application is in low idle current.
    When the path of protect diode is connection, the current will flow to the protection diode in the idle mode at 6V Power .
    It will consume extra current. Is it right?

    Best Regards,
    Sheng Hua
  • 0 in reply to ShengHua Yang
    TI__Guru** 105361 points
    Hi ShengHua,
    Yes, additional power loss equivalent to diode drop * device supply current.

    Regards
    Rakesh