Filter
Top Products
www.ti.com
1Overview
1.1Features
1.2PowerRequirements
1.2.1SupplyVoltage
1.2.2ReferenceVoltage
Overview
ThissectiongivesageneraloverviewoftheDAC8555EVManddescribessomeofthefactorsthatmust
beconsideredwhenusingthisdemonstrationboard.
TheDAC8555EVMisasimpleevaluationmoduledesignedforaquickandeasywaytoevaluatethe
functionalityandperformanceofthehigh-resolution,quad-channel,serialinputDAC8555digital-to-analog
converter(DAC).ThisEVMfeaturesaserialinterfacetocommunicatewithanyhostmicroprocessororTI
DSP-basedsystem.
Thissubsectiondescribesthepowerrequirementsforthisdevice.
TheDCpowersupplyrequirementforthedigitalsection(V
DD
)ofthisEVMistypically+5Vconnectedto
theJ5-1terminalorviatheJ3-10terminal(whenpluggedinwithanotherEVMboardorinterfacecard)
andisreferencedtogroundthroughtheJ5-2andJ3-5terminals.TheDCpowersupplyrequirementsfor
theanalogsectionofthisEVMare:V
CC
andV
SS
rangefrom+15.75Vto–15.75V(maximum),connecting
throughJ1-3andJ1-1respectively,orthroughterminalsJ3-1andJ3-2.The+5V
A
connectsthrough
terminalsJ5-3orJ3-3,andthe+3.3V
A
connectsthroughterminalJ3-8.Alloftheanalogpowersupplies
arereferencedtoanaloggroundthroughterminalsJ1-2andJ3-6.
Theanalogpowersupplyforthedeviceundertest,U1,canbepoweredbyeither+5V
A
or+3.3V
A
by
selectingtheproperpositionofjumperJMP7.ThisconfigurationallowstheDAC8555analogsectionto
operatefromeithersupplypowerwhiletheI/Oanddigitalsectionarepoweredby+5V,V
DD
.
TheV
CC
supplysourceisprimarilyusedtoprovidethepositiverailoftheexternaloutputopamp,U2,the
referencechip,U3andthereferencebuffer,U4.Thenegativerailoftheoutputopamp,U2,canbe
selectedbetweenV
SS
andAGNDviajumperJMP10.Theexternalopampisinstalledasanoptionto
provideoutputsignalconditioningortoboostcapacitiveloaddrive,orforotherdesiredoutputmode
requirements.
CAUTION
ToavoidpotentialdamagetotheEVMboard,besurethatthecorrectcables
areconnectedtotheirrespectiveterminalsaslabeledontheEVMboard.
Stressesabovethemaximumlistedvoltageratingsmaycausepermanent
damagetothedevice.
The+5VprecisionvoltagereferenceisprovidedtosupplytheexternalvoltagereferencefortheDAC
throughtheREF02(U3)viajumperJMP8,byshortingpins1and2.Thereferencevoltagegoesthrough
anadjustable100kΩpotentiometer,R15,inserieswith20kΩ,R16,toallowtheusertoadjustthe
referencevoltagetoitsdesiredsettings.ThevoltagereferenceisthenbufferedthroughU4Aasseenby
thedeviceundertest.ThetestpointsTP2,TP3andTP4arealsoprovided,aswellasJ4-18andJ4-20,in
ordertoallowtheusertoconnectanotherexternalreferencesourceiftheonboardreferencecircuitisnot
desired.Theexternalvoltagereferenceshouldnotexceed+5VDC.
TheREF02precisionreferenceispoweredbyV
CC
(+15V)througheitherterminalJ1-3orJ3-1.
SLAU204–December2006DAC8555EVMUser'sGuide3
SubmitDocumentationFeedback