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TPS53313: Vin leakage issue

Part Number: TPS53313
Other Parts Discussed in Thread: TPS53312, TPS54326

Hi

when I use TPS53312 ,  (I can not find TPS53312 in Part number)

when the system have abnormal voltage on "Sw" pin, it causes leakage on "Vin " pin .

how to prevent phenomena?

 

  • Hi Dimitry,

    TPS53312 is now replaced by TPS54326. You can check that datasheet.

    Can you elaborate on what the abnormal voltage on SW pin means? What is the voltage on SW pin and VIN pin when the leakage happens?

    A common scenario is when current flows from output to input through the high-side FET body diode if VIN is not present or is lower than VOUT (could be a quick ramp down during shutdown while VOUT persists). This current needs to be kept lower than the forward current rating of the IC, in this case, 3A or lower. Also, you need to ensure the IC does not heat up due to the losses in body-diode. If you suspect any of these issues, you can add an external diode between the supply and the IC to prevent the reverse current flow.

    Thanks,

    Amod

  • Hi Amod

    What I am see in my design, the issue  it's " current flows from output to input through the high-side FET body diode "

    Does TPS53312  also have the same issue?

    or could you tell which POL can prevent the issue?

  • Hi Dimitry,

    Unfortunately, yes TPS53312 and just about any converter will have this reverse current flow if VOUT > VIN. Like I mentioned this is usually not an issue if the reverse current flowing through is not high and does not heat up the IC. You will however need to protect any other devices connected to the input. Since this is a low current, you can just add a diode between the supply and VIN pin of the IC to prevent the reverse current flow.

    Here are two app notes that you can read about this and possible alternative solutions:

    https://www.ti.com/lit/an/slyt689/slyt689.pdf (check figure 3)

     https://www.ti.com/lit/an/slva730/slva730.pdf

    Thanks,

    Amod