第三节-开关电源电压型控制和电流型控制基本原理

VoltageModeControl)(CurrentModeControl)PWMPWMx-C1M1Vdcu(t)C1z=xyR3D5+D12D4R1D2D1Vo-+R20VrefL12PIPWMX•1.•2.•3.hiccup-mode),•4.TL494,SG3525•1•2•31.,;2.LC,;3.,4PID)PWM1.t0t1t2t3t4t5VgiRiSiSCLKPIPWMPWMSRQSiRiSCLKiRiLiL’IL0t=0'LLLiii−=∆et=0M1M2DTsD’TsDDMM'21=21012,][MMeMMenn−=iRIL0t=0DTsD’Ts0'012][][50eDDeMMeDnnn−=−=sub-harmonic,]2/[]2/[112sssRLssQiiϖϖ++=∧∧ssMMMMQϖπ)(2)(2121+−=0,21≤≤sQMMiRIL0t=0DTsD’Ts,0,)(2)2(2121++−=sccsQMMMMMMQπMCM1M2012][eMMMMenCCn+−=12100Hz34UC3842/3/4/5/62.SiRiSuCuS,][012eMMMMenSSn+−=PWM1.;2.,,;3.,,1.,;2.,,50%,,;3.,;4.,,,5.50:;;;;,;():;,;,;;;