I´m desiging a LNK PH buck inductor and hava a basic question.
The specs of core EE20-10-5 are: AE=0,31Cm2; LE=4,3Cm; AL=1300nH/T^2.
Vin: 190 to 204V
Using a KP of 0,81 result in 482uH, 140 turns, gap lengt of 1,5mm.
But, the necessary gap lengt to obtain 482uH was 2mm.
In your practice, this values of 2mm or 1,5mm are too big values or are "normal" valures for a gap in a ferrite core?
If I use kp=1 the the peak current increase from 2,16A ( for a kp of 0,81) to 2,28A ( for a Kp=1). And of course, the inductance is lower, 328uH, less turns and lower gap. do you think that this difference of 120mA ( 2,28A-1,16A ) is an important "improvment" in this design or no? The current limit of lnk409 is 3,12A.