Hello , I met a problem that i used lm3429 for sepic circuit ,the frequency is not stable , when change output current , frequency would became bigger .
and i used formula frequency = 25/Rct *Crct ) =25/(47000*0.000000001)=531K,but measured frequency is 230K . I cant figure it out why frequency is strange..
Input voltage is 9 to 16v ,output is 12V,1A. thanks for you help in advance .