LT3071
5A, Low Noise,
Programmable Output, 85mV
Dropout Linear Regulator
with Analog Margining
FeAtures
Description
TheꢀLT®3071ꢀisꢀaꢀlowꢀvoltage,ꢀUltraFast™ꢀtransientꢀre-
sponseꢀlinearꢀregulator.ꢀTheꢀdeviceꢀsuppliesꢀupꢀtoꢀ5Aꢀofꢀ
outputꢀcurrentꢀwithꢀaꢀtypicalꢀdropoutꢀvoltageꢀofꢀ85mV.ꢀ
Aꢀ0.01µFꢀreferenceꢀbypassꢀcapacitorꢀdecreasesꢀoutputꢀ
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ꢀ Output Current: 5A
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Dropout Voltage: 85mV Typical
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Digitally Programmable V : 0.8V to 1.8V
OUT
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Analog Output Margining: 10ꢀ Range
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Low Output Noise: 25µV
(10Hz to 100kHz)
voltageꢀnoiseꢀtoꢀ25µV
.ꢀTheꢀLT3071’sꢀhighꢀbandwidthꢀ
RMS
RMS
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Parallel Multiple Devices for 10A or More
permitsꢀtheꢀuseꢀofꢀlowꢀESRꢀceramicꢀcapacitors,ꢀsavingꢀ
bulkꢀcapacitanceꢀandꢀcost.ꢀTheꢀLT3071’sꢀfeaturesꢀmakeꢀ
itꢀidealꢀforꢀhighꢀperformanceꢀFPGAs,ꢀmicroprocessorsꢀorꢀ
sensitiveꢀcommunicationꢀsupplyꢀapplications.ꢀ
Precision Current Limit: 20ꢀ
ꢀ OutputꢀCurrentꢀMonitor:ꢀI
ꢀ=ꢀI /2500
MON OUT
ꢀ 1ꢁꢀAccuracyꢀOverꢀLine,ꢀLoadꢀandꢀTemperature
ꢀ StableꢀwithꢀLowꢀESRꢀCeramicꢀOutputꢀCapacitorsꢀ
(15µFꢀMinimum)
Outputꢀvoltageꢀisꢀdigitallyꢀselectableꢀinꢀ50mVꢀincrementsꢀ
overꢀaꢀ0.8Vꢀtoꢀ1.8Vꢀrange.ꢀAnꢀanalogꢀmarginingꢀfunctionꢀ
allowsꢀtheꢀuserꢀtoꢀadjustꢀsystemꢀoutputꢀvoltageꢀoverꢀaꢀ
continuousꢀ 10ꢁꢀrange.ꢀTheꢀICꢀincorporatesꢀaꢀuniqueꢀ
trackingꢀfunctionꢀtoꢀcontrolꢀaꢀbuckꢀregulatorꢀpoweringꢀ
theꢀLT3071’sꢀinput.ꢀThisꢀtrackingꢀfunctionꢀdrivesꢀtheꢀbuckꢀ
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ꢀ HighꢀFrequencyꢀPSRR:ꢀ30dBꢀatꢀ1MHzꢀ
ꢀ EnableꢀFunctionꢀTurnsꢀOutputꢀOn/Off
ꢀ VIOCꢀPinꢀControlsꢀBuckꢀConverterꢀtoꢀMaintainꢀLowꢀ
PowerꢀDissipationꢀandꢀOptimizeꢀEfficiency
ꢀ PWRGD/UVLO/ThermalꢀShutdownꢀFlag
ꢀ CurrentꢀLimitꢀwithꢀFoldbackꢀProtection
ꢀ ThermalꢀShutdown
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regulatorꢀtoꢀmaintainꢀtheꢀLT3071’sꢀinputꢀvoltageꢀtoꢀV
+ꢀ300mV,ꢀminimizingꢀpowerꢀdissipation.ꢀ
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InternalꢀprotectionꢀincludesꢀUVLO,ꢀreverse-currentꢀprotec-
ꢀ 28-Leadꢀ(4mmꢀ×ꢀ5mmꢀ×ꢀ0.75mm)ꢀQFNꢀPackage
tion,ꢀprecisionꢀcurrentꢀlimitingꢀwithꢀpowerꢀfoldbackꢀandꢀ
thermalꢀshutdown.ꢀTheꢀLT3071ꢀregulatorꢀisꢀavailableꢀinꢀaꢀ
thermallyꢀenhancedꢀ28-lead,ꢀ4mmꢀ×ꢀ5mmꢀQFNꢀpackage.
ApplicAtions
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ꢀ FPGAꢀandꢀDSPꢀSupplies
L,ꢀLT,ꢀLTC,ꢀLTM,ꢀLinearꢀTechnologyꢀandꢀtheꢀLinearꢀlogoꢀareꢀregisteredꢀtrademarksꢀofꢀLinearꢀ
TechnologyꢀCorporation.ꢀUltraFastꢀandꢀVLDOꢀareꢀtrademarksꢀofꢀLinearꢀTechnologyꢀCorporation.ꢀꢀ
Allꢀotherꢀtrademarksꢀareꢀtheꢀpropertyꢀofꢀtheirꢀrespectiveꢀowners.ꢀPatentsꢀpending.
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ꢀ ASICꢀandꢀMicroprocessorꢀSupplies
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ꢀ ServersꢀandꢀStorageꢀDevices
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ꢀ PostꢀBuckꢀRegulationꢀandꢀSupplyꢀIsolation
typicAl ApplicAtion
Dropout Voltage
150
0.9V, 5A Regulator
V
= V
OUT(NOMINAL)
IN
50k
V
BIAS
2.2V TO 3.6V
PWRGD
120
90
60
30
0
2.2µF
BIAS
V
IN
1.2V
IN
EN
V
PWRGD
SENSE
V
BIAS
= 1.8V
= 3.3V
330µF
OUT
V
0.9V
5A
OUT
V
LT3071
OUT
O0
2.2µF*
4.7µF*
10µF*
V
O1
V
O2
V
V
= 0.8V
= 2.5V
OUT
BIAS
*X5R OR X7R CAPACITORS
V
MON
NC
2V AT 5A
MARGA
VIOC
I
MON
FULL SCALE
REF/BYP
GND
1k
0
1
2
3
4
5
1nF
0.01µF
OUTPUT CURRENT (A)
3071 TA01b
3071 TA01a
3071f
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