Crane Aerospace & Electronics Power Solutions
smHF sꢀꢁgꢂꢃ ꢄꢁꢅ dꢆꢄꢂ dc/dc cꢇꢁvꢃꢈꢉꢃꢈꢊ
28 Volt input – 15 Watt
Features
•ꢀ FullyꢀqualifiedꢀtoꢀClassꢀHꢀorꢀK
•ꢀ -55°Cꢀtoꢀ+125°Cꢀoperation
•ꢀ 16ꢀtoꢀ40ꢀVDCꢀinput
•ꢀ FullyꢀIsolated
•ꢀ Radꢀhardꢀoptocouplerꢀfeedback
•ꢀ Fixedꢀfrequency,ꢀ550ꢀkHzꢀtypical
•ꢀ Topologyꢀ–ꢀSingleꢀEndedꢀForward
•ꢀ Transientꢀprotectionꢀ50ꢀV/120ꢀmsꢀ
•ꢀ Inhibitꢀfunction
models
•ꢀ Syncꢀfunction
vDc
•ꢀ Indefiniteꢀshortꢀcircuitꢀprotection
•ꢀ Undervoltageꢀlockout
SIꢁꢂLE
DUAL
±5
±12
±15
2.5
3.3
5
•ꢀ Upꢀtoꢀ82%ꢀefficiency
12
15
description
theꢀoutputꢀloadꢀcurrentꢀandꢀprovidingꢀaꢀconstantꢀcurrentꢀoutputꢀ
aboveꢀtheꢀoverloadꢀpoint.ꢀ
TheꢀSMHFꢀSeries™ꢀofꢀ28ꢀVꢀDC/DCꢀconvertersꢀoffersꢀaꢀwideꢀ
inputꢀvoltageꢀrangeꢀofꢀ16ꢀtoꢀ40ꢀvoltsꢀandꢀupꢀtoꢀ15ꢀwattsꢀofꢀ
outputꢀpower.ꢀTheꢀunitsꢀareꢀcapableꢀofꢀwithstandingꢀshortꢀtermꢀ
transientsꢀupꢀtoꢀ50ꢀvolts.ꢀTheꢀpackageꢀisꢀaꢀhermeticallyꢀsealed,ꢀ
projection-weldedꢀmetalꢀcase.ꢀFlangedꢀandꢀnon-flangedꢀmodelsꢀ
areꢀavailable.ꢀ
HigHer Po w e r DenSity
TheꢀSMHFꢀSeriesꢀoffersꢀaꢀnewꢀstandardꢀofꢀperformanceꢀforꢀsmallꢀ
sizeꢀandꢀhighꢀpowerꢀdensity.ꢀAtꢀjustꢀ0.33ꢀinchꢀhighꢀandꢀaꢀtotalꢀ
2
footprintꢀofꢀ1.7ꢀin ,ꢀthisꢀlowꢀprofileꢀpackageꢀoffersꢀaꢀtotalꢀpowerꢀ
Screening
densityꢀofꢀupꢀtoꢀ30ꢀwattsꢀperꢀcubicꢀinch.ꢀ
SMHFꢀconvertersꢀofferꢀscreeningꢀoptionsꢀtoꢀSpaceꢀPrototypeꢀ(O),ꢀ
ClassꢀH,ꢀorꢀClassꢀK.ꢀRadiationꢀtolerantꢀtoꢀRadiationꢀHardnessꢀ
Assuranceꢀ(RHA)ꢀlevelsꢀofꢀ“-”ꢀ(O)ꢀorꢀ“R”,ꢀperꢀMIL-PRF-38534.ꢀ
Interpointꢀmodelꢀnumbersꢀuseꢀanꢀ“O”ꢀinꢀtheꢀRHAꢀdesignatorꢀposi-
tionꢀtoꢀindicateꢀtheꢀ“-”ꢀ(dash)ꢀRadiationꢀHardnessꢀAssuranceꢀlevelꢀ
ofꢀMIL-PRF-38534,ꢀwhichꢀisꢀdefinedꢀasꢀ“noꢀRHA”.ꢀSeeꢀ“ClassꢀHꢀ
andꢀK,ꢀMIL-PRF-38534ꢀScreening”ꢀtablesꢀforꢀmoreꢀinformation.
Low noiSe, HigH AuDio rejection
TheꢀSMHFꢀconverter’sꢀfeed-forwardꢀcompensationꢀsystemꢀ
providesꢀexcellentꢀdynamicꢀresponseꢀandꢀnoiseꢀrejection.ꢀAudioꢀ
rejectionꢀisꢀtypicallyꢀ50ꢀdB.ꢀTypicalꢀoutputꢀvoltageꢀresponseꢀforꢀ
aꢀ50%ꢀtoꢀ100%ꢀstepꢀloadꢀtransientꢀisꢀasꢀlowꢀasꢀ1.3%ꢀwithꢀaꢀ150ꢀ
µSꢀrecoveryꢀtime.ꢀInputꢀrippleꢀcurrentꢀisꢀtypicallyꢀ35ꢀmAꢀp-pꢀwithꢀ
outputꢀrippleꢀvoltageꢀtypicallyꢀ50ꢀmVꢀp-pꢀ.
converter DeSign
TheꢀSMHFꢀconvertersꢀareꢀswitchingꢀregulatorsꢀthatꢀuseꢀaꢀquasi-
squareꢀwave,ꢀsingle-endedꢀforwardꢀconverterꢀdesignꢀwithꢀaꢀ
constantꢀswitchingꢀfrequencyꢀofꢀ550ꢀkHz.ꢀIsolationꢀbetweenꢀinputꢀ
andꢀoutputꢀcircuitsꢀisꢀprovidedꢀwithꢀaꢀtransformerꢀinꢀtheꢀforwardꢀ
pathꢀandꢀaꢀtemperatureꢀcompensatedꢀopto-couplerꢀinꢀtheꢀfeed-
backꢀcontrolꢀloop.ꢀTheꢀopto-couplerꢀisꢀradiationꢀhardenedꢀandꢀisꢀ
especiallyꢀselectedꢀforꢀspaceꢀapplications.
inHibit Function
SMHFꢀconvertersꢀprovideꢀanꢀinhibitꢀterminalꢀthatꢀcanꢀbeꢀusedꢀ
toꢀdisableꢀinternalꢀswitching,ꢀresultingꢀinꢀnoꢀoutputꢀandꢀveryꢀlowꢀ
quiescentꢀinputꢀcurrent.ꢀTheꢀconverterꢀisꢀinhibitedꢀwhenꢀaꢀlogicꢀ
lowꢀ(≤0.8ꢀ–ꢀoutputꢀdisabled)ꢀisꢀappliedꢀtoꢀtheꢀinhibitꢀpin.ꢀTheꢀ
unitꢀisꢀenabledꢀwhenꢀtheꢀpin,ꢀwhichꢀisꢀinternallyꢀconnectedꢀtoꢀaꢀ
pull-upꢀresistor,ꢀisꢀleftꢀunconnectedꢀorꢀisꢀconnectedꢀtoꢀanꢀopen-
collectorꢀgate.ꢀTheꢀopenꢀcircuitꢀoutputꢀvoltageꢀassociatedꢀwithꢀtheꢀ
inhibitꢀpinꢀisꢀ8.5ꢀtoꢀ12ꢀVDC.ꢀInꢀtheꢀinhibitꢀmode,ꢀaꢀmaximumꢀofꢀꢀ
4ꢀmAꢀmustꢀbeꢀsunkꢀfromꢀtheꢀinhibitꢀpinꢀatꢀ28ꢀVDCꢀinput.
ForꢀtheꢀSMHFꢀdualꢀoutputꢀmodels,ꢀcrossꢀregulationꢀisꢀmaintainedꢀ
byꢀtightlyꢀcoupledꢀoutputꢀmagnetics.ꢀUpꢀtoꢀ70%ꢀofꢀtheꢀtotalꢀoutputꢀ
powerꢀisꢀavailableꢀfromꢀeitherꢀoutput,ꢀprovidingꢀtheꢀoppositeꢀ
outputꢀisꢀsimultaneouslyꢀcarryingꢀ30%ꢀofꢀtheꢀtotalꢀoutputꢀpower.ꢀ
Predictableꢀcurrentꢀlimitꢀisꢀaccomplishedꢀbyꢀdirectlyꢀmonitoringꢀ
CraneꢀAerospaceꢀ&ꢀElectronics
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Electronicsꢀꢂroupꢀ(InterpointꢀBrand)
POꢀBoxꢀ97005ꢀꢀ•ꢀꢀRedmondꢀWAꢀ98073-9705
425.882.3100ꢀꢀꢀ•ꢀꢀꢀelectronics@craneae.com
www.craneae.com
RevꢀDꢀ-ꢀ20070404
ClearedꢀbyꢀU.S.ꢀDoDꢀOSRꢀforꢀPublicꢀReleaseꢀꢀ
OSRꢀcaseꢀnumberꢀ09S-0995,ꢀdatedꢀMarchꢀ13,ꢀ2009.