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Rev. 1.10 1 July 17, 2013 Rev. 1.00 PB July 17, 2013
HT7A6005Low Power, Wide Temperature Range General
Purpose Current Mode PWM Controller
Feature
HighPerformance,LowCostCurrentModePWMControllerespeciallydesignedforEnergyStar5.0
VeryLowStartupCurrent(3KV)
5%TrimmedOscillatorforPreciseFrequencyControl
LEB(Leading-EdgeBlanking)onCSPin
InternalSlopeCompensation
ProgrammableSwitchingFrequency
InternallyTrimmedReferencewithUVLO(UnderVoltageLockout)
Cycle-by-CycleCurrentLimiting
Applications SwitchingAC-DCAdaptors
DC-DCSwitchingBuck/BoostConverters
LEDBacklightsforLCD/LEDTVs
General DescriptionTheHT7A6005 isacontroller IC that includes
thenecessaryfeatures to
implementoff-lineorDC-DCcurrentmodecontrolschemeswithaminimalexternalparts
count. Internal circuits include a
speciallydesignedMixed-Mode/Analog Interface
formulti-functionandmulti-topologycontrolschemes(DC-DCBuck/Boost,Off-lineAC-DC),a
trimmedoscillatorforpreciseduty-cyclecontrolundervoltagelockoutwithastart-upcurrentof
less
than0.5mA,awidetemperaturerange,precisevoltagereference,internalSlopeCompensationandLeading-EdgeBlanking.TheHT7A6005
features basic
systemprotectionfunctionssuchasCycle-by-CycleCurrentLimitingandUnderVoltageLock-Out(UVLO).
AMulti-FunctionPin canbeused as a
dimmingfunctionforLEDdriving,andasaprimaryfeedbackcont ro l for Pr
imary-Side Feedback AC-DCapplications.
Application Circuits
GD
VCC
MFCS
COMP/FB
GND
RT
VREF
2.2kW0.1mF
470mF/50V
10W 1N4148
20W
0.22W
10kW
IRF540
0.22W
1nF
470kW
33pF
HFB20HJ20C
0.1mF/100V
46mH
2kW
40kW
470mF/63V820W
220pF
Vo=55V/75W
VIN=24V
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Rev. 1.10 2 July 17, 2013
HT7A6005
Block Diagram Pin Assignment
32V
UVLO
14V / 8V
Internal Bias& Vref
Trimmed OSC
OCP OutputLEB
350ns
S
R
Q
DriverStage
8VREF
VCC
GD
GND
VCC
RT
COMP/FB
CS
MF
OCP Level = 1V
FB CompareLevel = 2.5V
Slope Compensation
3
6
7
2
1
4
5
Mixed-Mode/AnalogInterface
Pin DescriptionPin No. Pin Name Description
1 COMP/FB Voltage Feedback Pin, Connected to a system voltage
feedback point.
2 MFMulti-Function Pin. By connecting this pin to different
system sensing points, the device can be used for different circuit
topologies such as Isolation Flyback or Non-Isolation DC-DC
Buck/Boost.
3 CS A voltage proportional to the inductor current is connected
to this input. The PWM generator uses this voltage to terminate
output switching.
4 RT The oscillator frequency is programmed by connecting a
resistor, RT, between this pin and ground. A maximum frequency of
500kHz is possible.
5 GND Combined control circuitry and power ground.
6 GD Power MOSFET gate driver output.
7 VCC Positive Supply.
8 VREF Temperature-independent voltage reference output.
Absolute Maximum
RatingsSupplyVoltageVCC................................................................................................................................
-0.3V~30.0V
COMP/FB,RT,CS,MFPins.....................................................................................................................
-0.3V~5.0V
JunctionTemperature..........................................................................................................................................
150C
OperatingAmbientTemperature...............................................................................................................
-40C~85C
StorageTemperatureRange....................................................................................................................
-65C~150C
PackageThermalResistance(8-PinSOP).....................................................................................................
160C/W
ESDProtection:
HumanBodyModel.......................................................................................................................................3kV
MachineModel............................................................................................................................................200V
Note:Thesearestressratingsonly.StressesexceedingtherangespecifiedunderAbsoluteMaximumRatings
maycausesubstantialdamagetothedevice.Functionaloperationofthisdeviceatotherconditionsbeyond
thoselistedin thespecificationisnot
impliedandprolongedexposuretoextremeconditionsmayaffect
devicereliability.
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Rev. 1.10 3 July 17, 2013
HT7A6005
Electrical CharacteristicsUnless otherwise stated, this
specifications apply for 0C Ta 70C, VCC=15V, RT=10kW
Symbol Parameter Test Condition Min. Typ. Max. Unit
Supply Voltage (VCC Pin)
IST Startup Current VCC=7.7V 12 30 mA
ICC Operating Current VFB=VCS=0V 2.0 3.0 mA
VTL UVLO (Off) 7.0 7.6 8.2 V
VTH UVLO (On) 7.8 8.4 9.0 V
Reference Section
VREF Output Voltage Tj = 25C, IO = 1mA 4.85 5.00 5.15 V
VREF Line Regulation 12V VCC 25V 3 20 mV
VREF Load Regulation 1mA IO 10mA 4 25 mV
Current Sensing (CS Pin)
VCS(OFF) Maximum Input Voltage 0.9 1.0 1.1 V
tLEB Leading Edge Blanking Time 350 ns
Delay to Output 100 ns
Oscillator (RT pin)
fOSC Oscillator Frequency Tj=25C, RT=10kW 47 52 57 kHz
fOSCTA
Tempurature Stability -40C ~105C 5 %
fOSCVREF
Voltage Stability VCC=10V~25V 0.2 1.0 %
DMAX Maximum Duty 97 %
Gate Drive Output (GD Pin)
VOL Output Low Level VCC=15V, Isink=20mA 1 V
VOH Output High Level VCC=15V, Isource=20mA 9 V
tr Rising Time Tj=25C, Load Capacitance=1nF 50 150 ns
tf Falling Time Tj=25C, Load Capacitance=1nF 50 150 ns
Voltage Feedback (COMP/FB Pin)
VCOMP Open Loop Voltage COMP/FB pin open 5 V
VREFA Reference Voltage VFB/PDM=2.5V 2.42 2.50 2.58 V
ISINKA Output Sink Current VFB=2.7V, VFB/PDM=1.1V 2 7 mA
ISOURCEA Output Source Current VFB=2.3V, VFB/PDM=4.8V -0.5 -1.0
mA
VOHA VCOMP/FB High Voltage VFB=2.3V, RL=15kW to GND 4.8 5.0
V
VOLA VCOMP/FB Low Voltage VFB=2.7V, RL=15kW to Vref 0.8 1.1
V
AVO DC Gain 150 dB
Note:TheseParameters,althoughguaranteed,arenot100%testedinproduction.
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Rev. 1.10 4 July 17, 2013
HT7A6005
Typical Performance Characteristics
Figure 1. UVLO (on) (V) vs Temperature
4748495051525354555657
-40 -20 0 20 40 60 80 100 120
Temperature (degree C)
Freq
uenc
y (K
Hz)
Figure 3. Frequency vs Temperature
Figure 2. UVLO (off)(V) vs Temperature
4748495051525354555657
11 13 15 17 19 21 23 25
Vcc (V)
Freq
uenc
y (K
Hz)
Figure 4. Frequency vs Vcc
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Rev. 1.10 5 July 17, 2013
HT7A6005
Application Information
Operation OverviewTheHT7A6005 isa lowpower,wide
temperaturerangegeneralpurposecurrentmodePWMController.Thedevice is
designed to require aminimumofexternal components for different
power
circuittopologiessuchasPrimary-SideFeedbackFlybackandDC-DCBuck/Boost.ThedevicecanbeusedforLEDdrivingapplications
suchasLEDbacklightsandLED lighting.TomeetLEDconstant
currentrequirements, thedevicecanmaintaina
lowcurrenttoleranceof1%forLEDdrivingapplications.
Under Voltage Lockout (UVLO)AUVLOcomparator isprovided toensure
that thedevice is fullyfunctionalbefore theoutputstage
isenabled.AsshowninFigure5,hysteresisisprovidedtoprevent
thePWMControllerfromshuttingdownduringanyvoltagedipswhichmightoccurduringthestartupprocess.The
turn-onand turn-off
thresholdlevelsaresetat8.4Vand7.6V,respectively.
Figure 5. UVLO Scheme and Start-Up Current
Current Sense and Leading-Edge Blanking (LEB)For Isolation
Flyback applications, a Leading-EdgeBlankingScheme is
necessary.ALeading-EdgeBlankingSchemeisintegratedinthedevicetopreventfalsetriggeringduetofeedbackcurrentspikeswhichmayappearon
theCSpin.ThiseliminatestheneedfortheusualR-CfilterwhichisnormallyarequirementintypicalcurrentmodePWMControllerapplications.
HT7A6005
350nsBlank Time
removedRT GD
GND
CS
VREF
0.1uF
10K
Figure 6. LEB with R-C Filter Removed
Internal Slope-CompensationAn important issuewith currentmode
controlschemesisinstabilityduetosub-harmonicoscillationwhentheDuty-Cycle>50%.Topreventthisproblemfromoccurring,
a Slope-Compensation functionis always necessary. In traditional
currentmodecontrollerapplications,manyexternalcomponentsarenecessary
to implementaSlope-Compensationfunction.However in theHT7A6005 the
internalSlope-Compensationfunctioneliminatestheneedfortheseexternalcomponentsresulting
inasimplifiedapplicationcircuitdesign.
Oscillator Frequency
TuningBychoosinganappropriatevalueofexternalresistorbetween
theRTPinandGND,asuitableoperatingfrequencycanbegenerated.TherelationshipbetweentheRTvalueandtheoperatingfrequencyisprovidedinFigure7.
Figure 7. RT Resistor Value vs. Operating Frequency
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Rev. 1.10 6 July 17, 2013
HT7A6005
GD
VCC
MFCS
COMP/FB
GND
RT
VREF
2.2kW0.1mF
470mF/50V
10W 1N4148
20W
0.22W
10kW
IRF540
0.22W
1nF
470kW
33pF
HFB20HJ20C
0.1mF/100V
46mH
2kW
40kW
470mF/63V820W
220pF
Vo=55V/75W
VIN=24V
Figure 8. Constant Voltage Boost Application (DC-DC Boost)
Multi-Function Pin
AspeciallydesignedMixed-Signal/AnalogInterfaceisprovided in
theHT7A6005.Byconnecting
theMulti-Function(MF)pintodifferentsystemsensingpoints,theHT7A6005canbeusedfordifferentcircuittopologiessuchasIsolationFlybackorNon-IsolationDC-DCBuck/Boost.TheMFpincanalsobeusedasanLEDdimmingpinforBuckLEDdriving.Someapplicationcircuit
examplesare introduced in thefollowingpages.
Constant Voltage Boost
ApplicationAConstantVoltage(CV)BoostapplicationcircuitisshowninFigure8.ThiscircuitcanbeusedwithDCinputsof16~24VandprovidesaDCoutputof55V5%with75Woutputpower.TheoutputpowerlevelcanbechangedbychoosingasuitableinductorvalueandpowerMOSFET,while
theoutputvoltagecanbechangedbychoosingasuitablefeedbackresistorratio.
Boost Constant Current (CC) LED Driver for Back-lightABoost
CCLEDDriver shown in Figure 9 isdesigned for LED backlight
applications.Thetopology is similar toBoost topologies, but
thefeedbackpoint ischangedfromtheVoltageOutputterminal to
theCurrentSenseResistor.ThiscircuitcanbeusedwithaDCinputof16~24VandprovidesaDCoutputof55Vwith75Woutputpower.ThiscircuitsconstantcurrentcapabilityismorethanthatrequiredbybacklightsandalsogoodenoughforLEDlightingapplications.
Buck Constant Current LED Lighting DriverA
lowcostBuckConstantCurrentLEDLightingdriver is introduced
inFigure10.Unlike theusualLEDdriveswhichhavea fixed-voltage
rangeandconstantcurrentcontrol,thiscircuitcansupportveryhighoutputvoltages,perhaps
forhighLEDcountserial configurations,with
nomaximumvoltagelimitations.HeretheMFpincanbeusedasaPWMdimmingpin.
Constant Voltage Buck ApplicationAConstantVoltage (CV)Buck
(High-SideBuck)applicationcircuitisshowninFigure11.ThiscircuitcanbeusedwithDCinputsof24Vorhighervoltageandprovides
aConstantDCvoltageoutput. Theoutputpower
levelcanbechangedbychoosingasuitable inductorvalue,Transformers
turnratioandpowerMOSFET,while
theoutputvoltagecanbechangedbychoosinga suitable feedback
resistorratio.
Primary Side Feedback, Isolation Flyback AC-DC
ConverterThedevicecanalsocanbeused for isolationAC-DCapplications.A
typicalprimaryside feedback,isolationFlybackAC-DC converter is
shown inFigure12.
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Rev. 1.10 7 July 17, 2013
HT7A6005
GD
VCC
MFCS
COMP/FB
GND
RT
VREF
2.2K0.1uF
470uF/50V
10 1N414820
0.2210K
IRF540
0.22
1nF
470K
33pF
HFB20HJ20C
0.1uF/100V
46uH
470uF/63V820
220pF
Vo=55V/75W
VIN=24V
Rs
OutputChannels
Figure 9. DC-DC Boost Constant Current (CC) LED Driver for
Back-light
GD
VCC
MF
CS COMP/FB
GND
RT
VREF
VIN
470uF/50V
Dimming
RT
RS
C1
Q1
D1
L1
Figure 10. Buck Constant Current LED Lighting Driver
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Rev. 1.10 8 July 17, 2013
HT7A6005
15
10k
1N4148
1N4148 1uF
10
100uF
1N41481nF
200
10k
5.1k
MBR160 220uF
47uH
5.1k
5.1k
Vout/5Vdc
56pF
1k
0.1uF 0.1uF
10nF
2.2k
1M
2SK941VIN=24Vdc
1 :
30
1 :
0.8
GDVCC
MF
CS
COMP/FBGND RT
VREF
Figure 11. Constant Voltage Buck Regulator (High-Side Buck)
F1
L1:A
L2:A
R3R7
R8 D4
D3
R4
R19
C12
GD
VCCMF
CS
COMP/FB
GND
RT
VREF
R11
C15
D1
C3R5
Vout
C14
T1
Q1
C11
U1
C1
C2
BD1Vac=90V~265V
L
N
R1
R21
5
4
3
7
8
C4
C13
R21
R22
R23
Figure 12. Primary Side Feedback, Isolation Flyback AC-DC
Converter
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Rev. 1.10 9 July 17, 2013
HT7A6005
Package InformationNotethat
thepackageinformationprovidedhereisforconsultationpurposesonly.Asthis
informationmaybeupdatedatregularintervalsusersareremindedtoconsulttheHoltekwebsiteforthelatestversionofthepackageinformation.
Additionalsupplementaryinformationwithregardtopackagingislistedbelow.Clickontherelevantsectiontobetransferredtotherelevantwebsitepage.
FurtherPackageInformation(includeOutlineDimensions,ProductTapeandReelSpecifications)
PackingMeterialsInformation
Cartoninformation
PBFREEProducts
GreenPackagesProducts
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Rev. 1.10 10 July 17, 2013
HT7A6005
8-pin SOP (150mil) Outline Dimensions
SymbolDimensions in inch
Min. Nom. Max.A 0.228 0.244
B 0.150 0.157
C 0.012 0.020
C' 0.188 0.197
D 0.069
E 0.050
F 0.004 0.010
G 0.016 0.050
H 0.007 0.010
0 8
SymbolDimensions in mm
Min. Nom. Max.
A 5.79 6.20
B 3.81 3.99
C 0.30 0.51
C' 4.78 5.00
D 1.75
E 1.27
F 0.10 0.25
G 0.41 1.27
H 0.18 0.25
0 8
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Rev. 1.10 11 July 17, 2013
HT7A6005
Copyright 2013 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be
accurate at the time of publication. However, Holtek assumes no
responsibility arising from the use of the specifications
described. The applications mentioned herein are used solely for
the purpose of illustration and Holtek makes no warranty or
representation that such applications will be suitable without
further modification, nor recommends the use of its products for
application that may present a risk to human life due to
malfunction or otherwise. Holtek's products are not authorized for
use as critical components in life support devices or systems.
Holtek reserves the right to alter its products without prior
notification. For the most up-to-date information, please visit our
web site at http://www.holtek.com.
FeatureApplicationsGeneral DescriptionApplication CircuitsBlock
DiagramPin AssignmentPin DescriptionAbsolute Maximum
RatingsElectrical CharacteristicsTypical Performance
CharacteristicsApplication InformationOperation OverviewCurrent
Sense and Leading-EdgeBlanking (LEB)Internal
Slope-CompensationOscillator Frequency TuningMulti-Function Pin
Constant Voltage Boost ApplicationBoost Constant Current (CC) LED
Driverfor Back-lightBuck Constant Current LED
LightingDriverConstant Voltage Buck ApplicationPrimary Side
Feedback, Isolation FlybackAC-DC Converter
Package Information8-pin SOP (150mil) Outline Dimensions
