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TPS54320: condition of I/O short

Part Number: TPS54320

Hi Team.


I want to know condition of I/O short.

TPS54320 broke.
Vin and PH terminals are short circuited.

What is the condition of I/O short?


 Vin = 5V
 Iout = 600mA(MAX)

circuite.pdf

  • Hi team

    I have additional information.

    When Vout line is short circuited to another power line,
    TPS54320 broke.

     Vout = 3.5V
     another power = 10V

    I want to know the reason of I/O short.

    From data sheet, absolute voltage of PH terminal is MAX 20V.

    What is the reason?

  • Hello,

    If you short VOUT to a voltage greater than VIN, current can flow backwards through the body diode of the high-side FET. There is no way for the TPS54320 to limit current this way. Doing this could damage most buck converters with a n-channel high-side FET.

    It is also not surprising that shorting VIN to PH damages the part. This could cause erratic behavior and there are multiple ways the IC could potentially be damaged.

    Can you share some details why the VOUT short to 10V and the VIN to PH tests are being done?

    Best Regards,
    Anthony

  • Hello

    The cause of the VOUT short to 10V  was a human error.

    I short circuited incorrectly Vout and another power on the board.


    I don't carry out the VIN to PH test.

    When I short VOUT to another power(10V) on the board, the IC damaged.
    The inpout(Vin) and output(PH) were shorted short circuited.

  • Got it. Makes sense now. Most likely a large amount of current flowed backwards from PH to VIN through the body diode of the HS FET and burnt up the HS FET. The peak current limit can only limit the forward current when the HS FET is on.

    Let me know if you need any further help.