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3.1OverviewofMultipleModules
CTR = 0
CTR=CMPB
X
EN
SyncOut
Phase reg
EPWMxA
EPWMxB
SyncIn
Φ=0°
3.2KeyConfigurationCapabilities
OverviewofMultipleModules
Previouslyinthisuser'sguide,alldiscussionshavedescribedtheoperationofasinglemodule.To
facilitatetheunderstandingofmultiplemodulesworkingtogetherinasystem,theePWMmodule
describedinreferenceisrepresentedbythemoresimplifiedblockdiagramshowninFigure3-1.This
simplifiedePWMblockshowsonlythekeyresourcesneededtoexplainhowamultiswitchpowertopology
iscontrolledwithmultipleePWMmodulesworkingtogether.
Figure3-1.SimplifiedePWMModule
Thekeyconfigurationchoicesavailabletoeachmoduleareasfollows:
•OptionsforSyncIn
–Loadowncounterwithphaseregisteronanincomingsyncstrobe—enable(EN)switchclosed
–Donothingorignoreincomingsyncstrobe—enableswitchopen
–Syncflow-through-SyncOutconnectedtoSyncIn
–Mastermode,providesasyncatPWMboundaries—SyncOutconnectedtoCTR=PRD
–Mastermode,providesasyncatanyprogrammablepointintime—SyncOutconnectedtoCTR=
CMPB
–ModuleisinstandalonemodeandprovidesNosynctoothermodules—SyncOutconnectedtoX
(disabled)
•OptionsforSyncOut
–Syncflow-through-SyncOutconnectedtoSyncIn
–Mastermode,providesasyncatPWMboundaries—SyncOutconnectedtoCTR=PRD
–Mastermode,providesasyncatanyprogrammablepointintime—SyncOutconnectedtoCTR=
CMPB
–ModuleisinstandalonemodeandprovidesNosynctoothermodules—SyncOutconnectedtoX
(disabled)
ForeachchoiceofSyncOut,amodulemayalsochoosetoloaditsowncounterwithanewphasevalue
onaSyncInstrobeinputorchoosetoignoreit,i.e.,viatheenableswitch.Althoughvariouscombinations
arepossible,thetwomostcommon—mastermoduleandslavemodulemodes—areshowninFigure3-2.
70ApplicationstoPowerTopologiesSPRU791D–November2004–RevisedOctober2007
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