This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS2553-1: About Internal current-limit MOSFET

Guru 21045 points
Part Number: TPS2553-1
Other Parts Discussed in Thread: TPS2553, TPS25221,

Hi Team,

 

I would like to know about Internal current-limit MOSFET.

I understand that Internal current-limit MOSFET in Driver block.

Is my understanding correct?



 

Regards,

Kanemaru

  • Hi, Kanemaru,

    The internal current limit MOSFET is actually the N-channel MOSFET you marked. TPS255x use this MOSFET to shutdown and limit current.

    Regards,
    Bob

  • Hi Bob-san,

     

    Thank you for the information.

    I would like to know the mean of the following comment.

    “the current-sense amplifier is overdriven during this time and momentarily disables the internal current-limit MOSFET.”

     

    I understand that when overcurrent (tIOS is 2us(typ)), the internal current-limit MOSFET don’t disable.

    Is my understanding correct?

     

    If no, could you please let us know the recovery time of MOSFET (From Disable to Enable)?

     

    Regards,

    Kanemaru

  • Hi, Kanemaru-San,

    You are correct, the internal current limit MOSFET(Power FET) don't disable at the beginning of short, and it finally shutdown after 2us of hot short. Or you can think that TPS2553 take 2 us to disable the FET.

    Regards,
    Bob
  • Hi Bob-san,

    Thank you for your prompt reply.

    I understand. Thank you very much.

    Regards,

    Kanemaru

  • Hi Bob-san,

     

    I understand that the internal MOSFET finally shutdown (OFF) after 2us of hot short.

    Then, could you please let us know the recovery time (from OFF to ON)?

     

    According to our customer, after around 2us of hot short, MOSFET is disabled during around 4ms.

    Therefore, they would like to know the recovery time (min / typ / max valuse).

     

    Regards,

    Kanemaru

  • Hi, Kanemaru,

    Thank your interest in our parts. Don't feel sorry for asking any questions, it's our pleasure to help you.

    You are correct, the current limit can't work at these two condition. There's a typical waveform in datasheet as below:

    You can see the current can't be limited at tIOS and then part is disabled. After sometimes(~300us in below waveform), the power FET enable again and current is limited.

    I don't have TPS2553 hot short waveform, below is TPS25221 hot short waveform FYI. TPS25221 is cost down version of TPS2553, the hot short waveform should be same.

    Feel free to ask any questions.

    Regards,
    Bob

  • Hi Bob-san,

     

    Thank you for always kind support.

    Do you have the recovery time data of TPS2553-1?

    And, could you please let me know your e-mail address?

    I would like to share the customer information and waveform.

    I’m looking forward to hearing from you.

     

    Regards,

    Kanemaru

  • Hi, Kanemaru-san,

    Since we have solved the problem by email, I will close this thread. Feel free to ask if any other questions.

    Regards,
    Bob
  • Hi Bob-san,

    Thank you for your response.

    I understand. Thank you very much.

    Regards,

    Kanemaru