SWITCHMODEâ¢ Power Supply Reference Manual

More documents

Recommendations

Info

SMPSRMFactors 3, 4 and 5 have a direct affect upon thereliability of the system. Switching power suppliesdeliver constant power to the output load. This power isthen reflected back to the input, so at low input voltages,the input current must be high to maintain the outputpower. Conversely, the higher the input voltage, thelower the input current. The design goal is to place asmuch as possible of the input voltage across thetransformer or inductor so as to minimize the inputcurrent.Boost–mode topologies have peak currents that areabout twice those found in forward–mode topologies.This makes them unusable at output powers greater than100–150 watts.Cost is a major factor that enters into the topologydecision. There are large overlaps in the performanceboundaries between the topologies. Sometimes the mostcost–effective choice is to purposely design one topologyto operate in a region that usually is performed byanother. This, though, may affect the reliability of thedesired topology.Figure 4 shows where the common topologies are usedfor a given level of DC input voltage and required outputpower. Figures 5 through 12 show the commontopologies. There are more topologies than shown, suchas the Sepic and the Cuk, but they are not commonlyused.1000Half–BridgeDC INPUT VOLTAGE (V)10042.510FlybackNon–IsolatedBuckFull–BridgeFull–BridgeVery HighPeak Currents10100OUTPUT POWER (W)1000Figure 4. Where Various Topologies Are Usedhttp://onsemi.com9
SMPSRM+V in–C in<strong>Power</strong> SwitchControlLDVC in in+Control SW +C out V outV DI LOAD IMINLV FWD+0V inD+ V outC outI LFeedback–0Figure 5. The Buck (Step–Down) ConverterV FLBKDV SWV SAT ONSW ON–I LV inI PKFigure 6. The Boost (Step–Up) Converter00I PKI SWI DDONTIMETIMETIMETIME+Control SWDV in C in–+L C out V out–+FeedbackV LI L00I SWI DV inI PK–V outTIMETIMEFigure 7. The Buck–Boost (Inverting) ConverterV FLBK+N1 N2CinV inControlSWDC out++V out–V SW0I PRI0V inV SATI PKSWONTIMETIME–FeedbackI SEC0TIMEFigure 8. The Flyback Converterhttp://onsemi.com10
Page 1 and 2: SMPSRM/DRev. 3, Jul-2002SWITCHMODE
Page 3 and 4: SMPSRMON Semiconductor and are regi
Page 6 and 7: SMPSRMIntroductionThe never-ending
Page 8 and 9: SMPSRMThe Flyback-Mode ConverterThe
Page 12 and 13: SMPSRM+N1 N2C inV inControlTSWDL OC
Page 14 and 15: SMPSRMInterleaved Multiphase Conver
Page 16 and 17: SMPSRMV CCOSCChargeClock RampV erro
Page 18 and 19: SMPSRMThe Power MOSFETPower MOSFETs
Page 22 and 23: SMPSRMThe Magnetic ComponentsThe ma
Page 24 and 25: ÉÉ ÂÂÂÂÂÂÂÂÂÂÂÉÉÉÉ
Page 26 and 27: SMPSRMThe forward conduction loss o
Page 28 and 29: SMPSRMSnubbers and ClampsSnubbers a
Page 30 and 31: SMPSRMThe Active ClampAn active cla
Page 32 and 33: SMPSRMIn this design, both the powe
Page 34 and 35: SMPSRMA Power Factor Correction (PF
Page 36 and 37: SWITCHMODE Power Supply ExamplesSMP
Page 38 and 39: V_SyncH_SyncMonitorMCUSYNC PROCESSO
Page 40 and 41: SMPSRMACLineRectifier+Start-upSwitc
Page 42 and 43: http://onsemi.com41Part No. VRRM(V)
Page 44 and 45: SMPSRMApplication: Compact Power Fa
Page 46 and 47: SMPSRMFeatures:Off power consumptio
Page 48 and 49: SMPSRMFeatures:70 W output power fr
Page 50 and 51: SMPSRMFeatures:Off power consumptio
Page 52 and 53: SMPSRMApplication: 110 W Output Fly
Page 54 and 55: SMPSRMApplication: Efficient Safety
Page 56 and 57: SMPSRMApplication: AC-DC Battery Ch
Page 58 and 59: SMPSRMLiterature Available from ON
Page 60 and 61:
SMPSRMWeb Locations for Switching-M
Page 62 and 63:
Analog ICs for SWITCHMODE Power Sup
Page 64 and 65:
SMPSRMON SEMICONDUCTOR STANDARD DOC
show all

SWITCHMODEâ¢ Power Supply Reference Manual

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?

SWITCHMODEâ¢ Power Supply Reference Manual