SC4524DEVB View Datasheet(PDF) - Semtech Corporation

Part Name

Description

MFG CO.

SC4524DEVB

18V 2A Step-Down Switching Regulator

Semtech Corporation 

SC4524D

Applications Information (Cont.)

D1

12 =OS=)1W=_>VR=C(IN⋅I6(V4NDVC2O+⋅O=IV1O0L+DVOVI.+%⋅VD0OFVOI+FSLTralIODSVV⋅No−⋅eEWcihoICD)VgOosS⋅cV−⋅eo4D)pFu⋅Dpu(⋅RCF⋅15p1LFSoBErr(gsW⋅2SS1+ea1n−Ct(WAo4cs1asTRo−D8ayDeEbVF−6mlV)DI⋅iNaI(lN+F-Dooi)bCpntSOff)y1)NdeWERTR.ADLIDLIRCnCDDDDtcaRRO⋅44fh11oLsMMIVnIIVIaDCNL=N=LLeaEm==4SSOOsd==ROItitI=_>=_>sNVANVRdR=pi=NcCC(e(eVIIoSV6tDrNNIIp6(Vi4o6(V4aSecNtNrmSDheCDV(Vn22pOOaCCnnen++c⋅⋅H4OGO=Ir=dBIBnV1V100G4)vOLsL++DiaD5SNSnRRGCCVCC.VTAACO5NOVVasVeMVI.+I.+%gT2%TTDpA⋅⋅VVD0D0OO2DFKOFViV7n7PotcO455M88CCOroIIeY++D4IIiWPODnOSVDSVtjDV⋅NV⋅NU−D−u⋅o⋅EWE=nD====SeWW==IL==SIItMneDD))OVVhMAOOWnStWS⋅⋅trDTV−eVi−⋅⋅((tDD)o)1OEbF(0FC⋅D22⋅D22−−(⋅(⋅≈RRRhnoC1CR)⋅r1⋅11)L1sLFgFSSp0s.EiEdπe((oπππe222sW⋅W⋅SoSSiS1+G1+11+mo1r−−s(A(WFWAa2FAd⋅⋅d80011Cp0tCTIT11eD01t6iosPZ−D−D88nsAao41o1o⋅⋅g⋅R6−0−1)/)rsDD1ll⋅D⋅2⋅tD5noRRooaeG00R.FFω2DD9⋅s2m0))sSSggf7t71CShSPWpScep)⋅)o11−W1WWehC01aB)ro,3aM1G2(twpD0ot1t3⋅⋅1aku81(=1CyCeCro1h3ce⋅1+Ad.h⋅OL22tOiiRo⋅1+lRRtGCCCs6AAsdVVei222hSeet77Po.cs558CC/r..2e11vWm13Ra⋅V=ω====e===.VMOpk2⋅1EOaf⋅nU1Sω1r(01p22Uπ2−−≈iTQh1Re⋅n0gT>0p.F0i1πCπiq1π8222ntGg++mC−1V0≈aA3F2⋅u⋅O800g3CVCh0C1016issZo)e3nAR=1⋅⋅⋅OR⋅260n1/ti1ll⋅21DC5=2Rnooh0G00/R.cω⋅9⋅0OggCgπe71y1.ωPVSp⋅V4−W,021F⋅)n2,3O5BMG2(8p01)31n8(=01CF13⋅1F+AalPStcFTblicg TaaaIf8⋅noo22ne⋅Raoo⋅onn+hhiWiu61sdaneoovdcs222cSmnrdeics.k0sEleosdcu/ppuM..211utk131RbeS⋅nmdtparbωrt3)cf.dhrork(2⋅cRo1Elctomea⋅tevobnaRRωRRGCC⋅1CCGCCiCCAASiAAωoaeVVlVV o1crhπnnncuQz2onRn⋅cy0n777Po7cnoPo(co55Z88CC5588CCpnkFe0g1ecastbCklt1WV2sW:cv+tdhnCa−o==srn=========f0==≈======3ltMMaCOcdeo3aeeeCit⋅tveurnt)ssugh)o311ma1irRr(0(0Re222222−−22−−=l≈t≈vOaLFp1l⋅1t2tarelenrggos0f0r0.o.1oCeeπE1gπrZ=2 πpoπππuππ222t2220t/(G,sG⋅Se+mwo+m111rr−ooleraCvAOAF2FF2πF⋅ll⋅⋅nRf⋅o1800800o.oωtn6VCaC0eif0CCe11wV1140r1tpro0616-CsPsZPZf5ec,u,oA2AuFm⋅aftis,11n1r12⋅⋅O⋅⋅⋅R⋅Rl560⋅6r0eBrt1aOi1//8ttpRwp1llt1llc⋅2⋅2t)le5ca5ifRRRooR1oo3parngG0noG00p0R.oR.hωωuo0i9,⋅F97⋅)u00qtinggggg,7.Fu77.17a1odunPt P(nSmS0p3p⋅r⋅hctuaC⋅−−hWWeitp0Fr1t01h))cn1o,3,3ahaneeMG2AMG2((pi(t0e01c133.gnd0l11niandVsLi8f8()e(===s1C1Cao111us3iw3sScC⋅1t⋅13+OA+AtnvpCwini1⋅⋅2222yCrhR)Rssan⋅⋅i+i+sω⋅ef6a6s8sdte 5t222i22te24iap)t2SiSctfsclr.s.snZ.se7e//i.t5th..2..2111a1hoi2sn9131e3RRi⋅⋅rtrsofωω2=wosn..ilanoiirdk2⋅k2⋅1En1⋅Eeghft4n⋅(⋅.nnsn1n1S1SωauωieRRB11ππgaDotfQgQaRFR⋅⋅cl00en0c4ppFiiF0l01E1DwnCCP 1.1nesyrhrS++dC−C−1faT−00≈e≈a33CROOsr33iC6fCtecnChn(etCsssua)o)33tGRlRr=g=idOeOO⋅q⋅2go2⋅nhnsOr11CCCa=2d=o21t3us0dae0i/c/⋅A⋅,fRonieOOerπrπ=ne.tn.11..ωωVcV063renVpV44idsnd),,a1oo22F⋅F⋅(nqn22Oi,Oel,55BBcRgm888onpnp))urttlnnysn.=o0t0FhhFt5=lpeitFFroaneee1)on5⋅⋅ltF.doi11hd5l.fcSFrc5Ti(piWlee00yeni8.oohimg,91m.1nr()g33noveucdoW(otpFaωu⋅ω⋅rRBEuro2ei2ils)rognAZ,Zttura22aolp7teui)==tnngh,fnut⋅e⋅ridgoeee1aa1RsRttr 00EESS11−−RR66CC⋅⋅OO1133,,

..00

..3

COMP

C5

C8

R7

CCo

8

=

1R4

2 πFP1 R 7

Resr

R6

Since the converter gain has only one dominant pole at

low frequency, a simple Type-2 compensation network

is sufficient for voltage loop compensation. As shown in

Figure 8, the voltage compensator has a low frequency

Figure 7. Block diagram of control loops

integrator pole, a zero at FZ1, and a high frequency pole

at FP1. The integrator is used to boost the gain at low

frequency. The zero is introduced to compensate the

excessive phase lag at the loop gain crossover due to the

13

Share Link: