Tool/software: WEBENCH® Design Tools
Hi,
We are using the "LM27402" buck controller for converting Vin=3.3V to Vout=1V@10A. For this design, we need a soft start delay tss=5ms. For this delay, the WEBENCH is recommending to use a capacitor of Css=47nF. But as per the formula mentioned in the datasheet of "LM27402" if we substitute the value of Css=47nF,
tss=Css*0.6/Iss,
=> tss= 47nF*0.6/3uA,
=> tss= 9.4ms
So, can you please suggest which one is reliable. Our requirement is we need a soft start delay tss=5ms, can we take the WEBENCH simulation report capacitor value or we need to calculate it as per the datasheet. ?