被动元件(电阻,电容,电感)之特性

1、, , Resistor characteristics . Ohms law()Î9 , 5 9 5 , . Power consumption()Î3 , 9 , 39 5 59 5 , Functions of Capacitor. Filter ÆThe impedance of capacitor (given capacitance C)ZC= 1/(sC) = 1/(jwC) = 1/(j2fC) then,the lower frequency f, the higher impedance ZCÆDC signal could be b

2、locked Æhighpass filter . Energy storage & transformation ÆW = (1/2) * C * V2(: )capacitor characteristics (OHFWULFDO FKDUDFWHULVWLFÆ,& & G9& GW9&±2,&Functions of Inductor . Filter ÆThe impedance of inductor (given inductance L)ZL= sL = jwL = j2fLthen

3、,the higher frequency f, the higher impedance ZLÆhigh frequency noise could be blocked Ælow pass filter . Energy storage & transformation Æ: / , (: )Inductor characteristics (1/3) (OHFWULFDO FKDUDFWHULVWLF+VL-Æ9/ / G,/GWLvolt-second theorem ()VON* TON= VOFF* TOFFInductor char

4、acteristics (2/3)Power Loss () = Copper loss () + Core loss () ÆCopper loss :I2L* RDC,RDC. Skin effect()(skin depth) d = 66 / (frequency)1/2(unit: mm). DCR or RDCR = T* L / Au ohm; Unit: L (mm), A (mm2)0T : Resistivity of copper at T C, (uohm*mm)T= *(1+0.004*T) = 1.588*(1+0.004*100) u ohm*mm, i

5、f T = 1000CInductor characteristics (3/3)Æ(Core loss) a. (core material)b. (operation frequency)c. (peak flux density)B8PK= (L* IP-P*10) / (2*A*N), A: , N: , L: , I(1Tesla = 10000 Gauss)P-P: 8:Hysteresis loop % +%+O 1,G% + O% (QHUJ -RXOH B:=³3GW=³ ,9 GW=³ ,GW=³,G=³% G 1

6、%$& = O& $& ³%+G% GW1WW W W W W7KH LQWHJUDWLRQ IURP % + FXUYH WR % DLV VKRZV WKH HQHUJ WUDQVIHU SHU YROXPH XQLW % + % Transformer . (IP) Æ(flux) Æ(-IS) , :(IS). (IP) Æ(flux) Æ(IS) capacitor characteristics (OHFWULFDO FKDUDFWHULVWLFÆ,& & G9& GW9&a

7、mp;±2,&4L)e ZL5ecnatcudni nev i gL(f rotc2ju d= nLi fwjo =e cLns ad=eLpZmi e , hrneTetlhiFÆt . dekcolb eb dluoc esion y crneetliuf qsesrfa hp gwiholÆÆ) :( , / :ÆFunctions of Inductor the higher frequency f, the higher impedanc. Energy storage & transformation -LLV+FL

8、WVWLUH GW F/D,UD GK F /O D FL/UW9FHOÆ( 6)FFOT *F(F mOVe r=oeNhOtT d*nNoOcVes-tlovInductor characteristics (1/3)( ssol eroC + )( ssol reppoC = )( ssoL rewoPCDR,CDR *2LI)mm :tinu(2/1)ycneuqerf( / 66 = d )htped niks()2mm() Am ,)mm*mmh( oLu (: t,inCU0;Tm tha or euppAo c /f Lo *ytTivCitD s=is ReR :

9、T7C001 = T fi ,mm*mho u =TInductor characteristics (2/3)ÆCopper loss :. Skin effect(). DCR or R= *(1+0.004*T) = 1.588*(1+0.004*100) )ssol eroC(Æ)ycneuqerf noitarepo( .b)N*A*2( / )801*P-PI *L( =KPB8 :P-P)ssuaG 00001 = alse T1(Inductor characteristics (3/3)a. (core material)c. (peak flux density), A: , N: , L: , I1,% & = O& $& ³%+G% XQLW 9$O+%G 1 O 1+ % ³%+=G, ³ =%WG WGG,W³W=WG 9, W ³W=%WG3W³W=:B HOXR- JUHQ( % + % :Hysteresis loop