LLC的原理与应用.ppt

* * * * * * * * * * * * * * * * * * * * * Operating Sequence below resonance (Phase 2/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 2/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q2 is ON, Q1 is OFF D1 and D2 are OFF transformer’s secondary is open Cr resonates with Ls+Lp, fr2 appears Output energy comes from Cout Phase ends when Q2 is switched off Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 3/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 3/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q1 and Q2 are OFF D1 and D2 are OFF transformer’s secondary is open Phase ends when Q1 is switched on Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 4/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 4/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q1 is ON, Q2 is OFF D1 is ON, D2 is OFF Lp is dynamically shorted Cr resonates with Ls, fr1 appears Energy is recirculating into Vin Phase ends when I(Ls)=0 Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 5/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 5/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q1 is ON, Q2 is OFF D1 is ON, D2 is OFF Lp is dynamically shorted Cr resonates with Ls, fr1 appears Energy is taken from Vin and goes to Vout Phase ends when I(D1)=0 Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 6/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 6/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q1 is ON, Q2 is OFF D1 and D2 are OFF transformer’s secondary is open Cr resonates with Ls+Lp, fr2 appears Output energy comes from Cout Phase ends when Q1 is switched off Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 7/8) Q1 ON Q2 OFF Q1 OFF Q2 ON Q1 OFF Q2 ON 7/8 Vin Vout Q1 Q2 Ls Lp Cr n:1:1 D1 D2 Coss1 Coss2 Q1 and Q2 are OFF D1 and D2 are OFF transformer’s secondary is open Phase ends when Q2 is switched on Cout Vg Vc I(lp) I(ls) Imos Id Operating Sequence below resonance (Phase 8/8)