www.德州仪器.com
描述/orderinginformation
PCA9306
dualbidirectionali2cbusandsmbusvoltage-leveltranslator
SCPS113–OCTOBER2004–REVISEDAPRIL2005
ThisdualbidirectionalI
2
candsmbusvoltage-leveltranslator,withanenable(en)输入,isoperationalfrom
1.2-vto3.3-vv
REF1
and2.5-vto5.5-vv
REF2
.
thepca9306allowsbidirectionalvoltagetranslationsbetween1.2vand5v,withouttheuseofadirectionpin.
thelowon-stateresistance(r
在
)oftheswitchallowsconnectionstobemadewithminimalpropagationdelay.
whenenishigh,thetranslatorswitchison,andthescl1andsda1i/oareconnectedtothescl2andsda2
i/o,各自,allowingbidirectionaldataflowbetweenports.whenenislow,thetranslatorswitchisoff,和
ahigh-impedancestateexistsbetweenports.
InI
2
capplications,thebuscapacitancelimitof400pfrestrictsthenumberofdevicesandbuslength.usingthe
pca9306enablesthesystemdesignertoisolatetwohalvesofabus;因此,morei
2
Cdevicesorlongertrace
lengthcanbeaccommodated.
thepca9306alsocanbeusedtoruntwobuses,oneat400-khzoperatingfrequencyandtheotherat100-khz
operatingfrequency.ifthetwobusesareoperatingatdifferentfrequencies,the100-khzbusmustbeisolated
whenthe400-khzoperationoftheotherbusisrequired.ifthemasterisrunningat400khz,themaximum
systemoperatingfrequencymaybelessthan400khzbecauseofthedelaysaddedbytherepeater.
AswiththestandardI
2
csystem,pullupresistorsarerequiredtoprovidethelogichighlevelsonthetranslator's
总线.thepca9306hasastandardopen-collectorconfigurationofthei
2
cbus.thesizeofthesepullupresistors
dependsonthesystem,buteachsideoftherepeatermusthaveapullupresistor.thedeviceisdesignedto
workwithstandard-modeandfast-modei
2
cdevices,inadditiontosmbusdevices.标准-modei
2
Cdevices
onlyspecify3mAinagenericI
2
csystemwherestandard-modedevicesandmultiplemastersarepossible.
undercertainconditions,highterminationcurrentscanbeused.
whenthesda1orsda2portislow,theclampisintheonstate,andalowresistanceconnectionexists
betweenthesda1andsda2ports.assumingthehighervoltageisonthesda2portwhenthesda2portis
高,thevoltageonthesda1portislimitedtothevoltagesetbyv
REF1
.whenthesda1portishigh,thesda2
portispulledtothedrainpullupsupplyvoltage(v
DPU
)bythepullupresistors.thisfunctionalityallowsa
seamlesstranslationbetweenhigherandlowervoltagesselectedbytheuser,withouttheneedfordirectional
控制.thescl1/scl2channelalsofunctionsasthesda1/sda2channel.
allchannelshavethesameelectricalcharacteristics,andthereisminimaldeviationfromoneoutputtoanotherin
voltageorpropagationdelay.thisisabenefitoverdiscretetransistorvoltagetranslationsolutions,sincethe
fabricationoftheswitchissymmetrical.thetranslatorprovidesexcellentesdprotectiontolower-voltagedevices
andatthesametimeprotectslessesd-resistantdevices.
ORDERINGINFORMATION
T
一个
包装
(1)
orderablepartnumbertop-sidemarking
(2)
Reelof3000PCA9306DCTR
ssop–dct7bd___
Reelof250PCA9306DCTT
–40°Cto85°C
Reelof3000PCA9306DCUR
vssop–dcu7bd_
Reelof250PCA9306DCUT
(1)packagedrawings,standardpackingquantities,thermaldata,符号化,andpcbdesignguidelinesareavailableat
www.德州仪器.com/sc/包装.
(2)dct:theactualtop-sidemarkinghasthreeadditionalcharactersthatdesignatetheyear,month,andassembly/testsite.
dcu:theactualtop-sidemarkinghasoneadditionalcharacterthatdesignatestheassembly/testsite.
2
: 点此下载
