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UCC28C43: Minimum ON time.

Christopher Ziel
Prodigy 10 points
Part Number: UCC28C43

Tool/software:

What is the minimum ON time of this controller?

  • 0
    TI__Genius 15566 points

    Cristopher, 

    You can find the minimum and maximum on time of the controller in the Datasheet, Electrical Characteristics section (see below).

    Thank you

  • 0
    Prodigy 10 points

    Hi Manual,

    I have considered this response however maybe I am not asking the right question.  Inside a switch cycle, what is the minimum duration the pass FET can be turned ON?  That is, once the controller has decided to turn the pass FET on, what is the minimum length of time the pass FET will remain ON before the controller decides it needs to be turned OFF?  Maybe there are internal conditioning delays in this chip which we are not aware of.  We are not seeing zero atto-seconds here, i.e. instant OFF.  We are seeing the appearance of a minimum number in our work.  Please advise.

  • 0 in reply to Christopher Ziel
    TI__Genius 15566 points

    Chrsitopher,

    -The minimum time a FET can be turned on depends primarily on the controller duty cycle that is commanded (Dmin*fsw). Then, you need to consider the delay on the gate driver to turn on and turn off the FET (check below rise and fall time from DS). You might also need to consider any delay between the (OUT-GND) driver signal from the controller to the actual gate to source of the main FET (that depends on your schematic and layout). Is not possible to give an exact number, as this depends on many variables.

    Thank you