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TPS25221: Reverse current blocking when VIN=0V

Genius 17325 points
Part Number: TPS25221

Tool/software:

Hello,

 I have a question for TPS25221.

It has reverse current blocking function when disabled.
Does it work even when VIN=0V?

I found a similar post regarding this topic, but it discussed whether it is damaged or not in this condtion.
I want to check if reverse current blocking correctly works in this condition.

Regards,
Oba

  • Hello Oba,

    Yes, when VIN=0V, reverse current will be blocked as long as the EN input is set above the threshold to enable the device.

    Thank you and best regards,

    Seong

  • Hello Seong,

    Thanks for your reply.
    But the reverse current shuld be blocked when it is disabled even if VIN=0V, meaning EN is BELOW 0.8V.
    Could you check again?

    Regards,
    Oba

  • Hello Oba,

    EN will be below 0.8V if VIN=0V if they are tied together. I believe I can safely assume that this is the case for you.

    Sure thing, I will look into this and let you know.

    Thank you and best regards,

    Seong

  • Hello Seong,

    Let me epxalin my question again. 

    EN is active HIGH pin for enable. The datasheet says that "Reverse Current Blocking (when disabled)” on the front cover like the below.


     

    So the reverse current should be blocked when EN is low(under 0.8V). My question is whether it is still true when VIN=0V.
    EN pin is controlled by the MCU in my case. MCU is powered, but TPS25221 is not powered.
    In this situation, whether TPS25221 can block the reverse current if EN is low. This is my question.

    >Yes, when VIN=0V, reverse current will be blocked as long as the EN input is set above the threshold to enable the device.

    From your 1st answer, you said that it will be blocked when EN is above the threshold which means the deivce is enabled.
    So I asked again. When EN=High, I think the reverse current may not be blocked. This is not my case.

    Regards,
    Oba

  • Hello Oba,

    Apologies for the confusion. Yes, you are correct:

    • Reverse current can only get blocked when the device is disabled, or when EN is under 0.8V.
    • When the device is disabled, reverse current can get blocked if VIN = 0V.

    Thank you and best regards,

    Seong

  • Hell Seong,

    Just to be sure, the reverse current works even if the VIN is not only 0V but also 0V~2.5V (out of recommended operating range) range, right?

    Regards,
    Oba

  • Hello Oba,

    Correct. There will be reverse current if the potential at VOUT is higher than VIN.

    Thank you and best regards,

    Seong

  • Hello Seong,

    Sorry, my question was not good.

    Now it is sure that VIN=0 & 2.5~5V, EN < 0.8V : Reverse current blocking works.

    My qustion is
    VIN=0~2.5V, EN < 0.8V: Reverse current blocking still work?

    Regards,
    Oba

  • Hi Oba,

    Yes, that is correct.

    BR,

    Seong