qinghezai:
我有個(gè)產(chǎn)品,該應(yīng)用是LED驅(qū)動(dòng)電路,采用非隔離降壓方案,CCM模式。輸入電壓——310V(整流后)電路的工作條件如下:Vdc=310V,Vo=72V,ton=D/f=1.7866us,Io=80mA,Dmax=0.2322,r=0.2~0.4,f=130k,△I=Io*r 從論壇搜索的資料,公式。計(jì)算如下: 計(jì)算1L={5*(Vinmax-Vo)*Vo*T}/Vinmax*Ion=(5*238*72*7.6923)/24.8=26.5756558mH 計(jì)算2L≥Uo(1-D)/(0.2*f*Io)=(72*(1-0.2322))/(0.2*130*0.08)=55.2816/2080=0.02657H=26.5776mH 計(jì)算3L(r=0.2時(shí))=(Vin-Vout)*ton/△I=238*1.7866/16=26.575675L(r=0.3時(shí))=(Vin-Vout)*ton/△I=238*1.7866/24=17.71711666666667L(r=0.4時(shí))=(Vin-Vout)*ton/△I=238*1.7866/32=13.28755625 計(jì)算4L=Vomax*(1-Vomax/Vdc)/0.2*Io*f=55.277424/2080=26.5756 結(jié)合以上公式計(jì)算得出,L=26.57mH。然而,實(shí)際應(yīng)用中,電感用的卻是3.3mHCD75,兩者相差甚遠(yuǎn),難以理解,請(qǐng)達(dá)人幫忙解惑,謝謝。是我計(jì)算錯(cuò)誤嗎?