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UCC28180: UCC28180 Question about ON/OFF Control and Vsense pin.

Bob Lee62837
Mastermind 7230 points
Part Number: UCC28180

Dear support member,

My customer used UCC28180.

I have a question.


(Question1)
The UCC 28180 has no ON / OFF pin.
How can IC control ON / OFF?


(Question2)
There are two as a threshold for the Vsense pin.
At soft start (-0.259 to -0.312 V).
At constant state (-0.345 to -0.438 V).


when setting the Vsense resistance,
since the constant state Vsense threshold is large, it will be higher than the soft start threshold.

Is there no problem even if it gets over current at startup?

Best regard.
Bob Lee.

  • 0
    TI__Mastermind 34465 points

    Hello Bob,

    The UCC28180 can be switched on/off or enabled/disabled by pulling VSENSE below the  open loop protection (OLP) level of 0.82V

    The answer to your second question is that the ISENSE input (not VSENSE input) has two thresholds.

    The lower threshold is for what we call a soft overcurrent (SOC) This is a nominal -0.285V
    The higher threshold is for a peak current limit (PCL) and this value -s a nominal -0.4V

    At startup you may get an over current but the inrush current is momentary and eventually the output capacitance will charge to the set voltage.

    Once this event is over the controller will return to normal operation.

    Regards

    John

  • 0 in reply to John Griffin1
    Mastermind 7230 points

    Dear John,

    Thank you very much for answer.

    Best regard.
    Bob Lee.

  • 0 in reply to Bob Lee62837
    TI__Mastermind 34465 points

    Hello Bob,

    I will go ahead and close this thread since I believe it has been answered fully.

    Please open a new post if you need further help.

    Regards

    John