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AL8860 Ton min

Winsu

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Hi All,

I am designing a LED board using the AL8860. My application would run from 30V ( Vin max) to Vout of 12.08 at 480mA. I don't have a problem with the nominal current , the problem comes when I reduce the current to a 10%. The datasheet states this:

1605979748215.png

I have done the calculation when I have 47mA of Iout and 11.04 V of Vo to calculate the Ton and it is less then 500ns( using an inductor of 440uH, which is bigger than I would like to use). Below is the equation:

1605979920120.png


I wonder if while using analog dimming mode I still have to calculate the Ton to know if the converter would do the switching properly or I just need to make the calculation for my nominal current and how the dimming current is just the 10% of the nominal( datasheet states it dim the current down to 5% ) I don't have to worry about it.

Any help would be useful? .
 

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