Rev. 1.10 1 August 23, 2012 HT7L2102 Anti-EMI, High Efficiency Dimmable LED Lighting Driver with Green Mode and Integrated Protections Feature • Frequency Jitter for EMI Restriction • Integrated Soft-Start Function • Very Low Operating Current and Start-up Current (<20mA) for satisfying Energy Star 5.0 "No-Load Mode" (Stand-by) Power standard • ±5% Trimmed Oscillator for Precise Frequency • Non-Audible-Noise Green Mode Control to maintain efficiency for both Light and Heavy Loads • LEB (Leading-Edge Blanking) on CS Pin • Internal Slope Compensation • Cycle-by-Cycle Current Limiting • Short-Circuit-Protection(SCP) for Short-Circuit and Over-Load Condition • Over-Voltage-Protection(OVP) on VCC Pin • Over-Temperature-Protection(OTP) on TS pin for External Thermistor Sensing • 1~99% PWM Dimming Range • 8-pin SOP package Applications • Isolation AC-DC LED Lighting • AC-DC Switching Power Supply/Adapter General Description The HT7L2102 is an advanced, highly integrated LED Lighting driver using an AC-DC isolation topology. The device provides many protection functions and uses ultra low power circuit design, and is optimized to restrict EMI. By integrating a Non-Audible Noise Green Mode Control Structure, users can implement a single circuit for different LED load levels for various series/parallel configurations but still maintain high efficiency for different load conditions. This device also integrates various protection functions for LED Lighting requirements such as Cycle-by-Cycle Current Limiting, Short-Circuit Protection (SCP), Over-Voltage Protection (OVP), Over-Temperature Protection (OTP) for external thermistor sensing, and a Soft-Start function to reduce inrush currents during LED power system initialization for the prevention of device burn-out. The HT7L2102 provides a 1~99% PWM Dimming Range with duty-cycle scale precision lower than 1%. Application Circuits R3 R7 D4 D3 R4 R19 C12 GD VCC TS ISENSE COMP/FB C19 GND RT Vref R11 C15 D1 R20 Vout C14 T1 Q1 U2 U1 C2 BD1 Vac=85V~265V L N 1 5 4 3 7 8 Q3 C4 Rts R28
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Rev. 1.10 1 August 23, 2012 Rev. 1.00 PB August 23, 2012
HT7L2102Anti-EMI, High Efficiency Dimmable
LED Lighting Driver with Green Mode and Integrated Protections
Feature FrequencyJitterforEMIRestriction
IntegratedSoft-StartFunction
VeryLowOperatingCurrentandStart-upCurrent(
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Rev. 1.10 2 August 23, 2012
HT7L2102
Block Diagram Pin Assignment
32V
UVLO
14V / 8V
Internal Bias& Vref
Green ModeOSC
LEB350ns
S
R
Q
DriverStage
VREF
VCC
GD
GND
VCC
RT
FB/PDM
ISENSE
TS
OCP Level = 1VFB Compare Level = 2.5V
Slope Compensation
3
6
7
2
1
4
5
Soft-Start
Frequency Jitter
OTPSCPOCP
OVP
8
Constant Current
Controller
Temperature Sense
107uA
Pin DescriptionPin No. Pin Name Description
1 FB/PDM Voltage Feedback Pin. Connected to a Photo-Coupler for closed-loop control. This pin also can be used as a PWM Dimming Pin.
2 TS Temperature Sense Pin. Connected to an external thermistor as a sense system hot point. This pin also can be used for an external System-Latch.
3 ISENSEA voltage proportional to the inductor current is connected to this input. The Constant Current Controller uses this voltage information to keep the system output current within a narrow range.
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 A Temperature-Independent Voltage Reference output.
Absolute Maximum RatingsSupplyVoltageVCC................................................................................................................................ -0.3V~30.0V
FB/PDM,RT,ISENSE,TSPins................................................................................................................ -0.3V~5.5V
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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Electrical CharacteristicsUnless otherwise stated, this specifications apply for 0C Ta 70C, VCC=15V, RT=10kW
Symbol Parameter Test Condition Min. Typ. Max. UnitSupply Voltage (VCC Pin)IST Startup Current VCC=12.9V 12 30 mA
ICC Operating CurrentVFB/PDM=0V 2.0 3.0 mAVFB/PDM=3V 2.5 mA
VTL UVLO (Off) 7 8 9 VVTH UVLO (On) 13 14 15 VVCC OVP Trip Level VCC(Over Voltage Protection) 26.5 28.0 29.5 VVD-OVP OVP Strobe Time 100 msReference Section (VREF Pin)VREF Output Voltage Tj=25C, IO=1mA 5.5 VVREF Line Regulation 12V VCC 25V 3 20 mVVREF Load Regulation 1mA IO 10mA 4 25 mVCurrent Sensing (ISE NSE Pin)VIS(OFF) Maximum Input Voltage, Vcs(off) 0.9 1.0 1.1 VtLEB Leading Edge Blanking Time 350 ns
Delay to Output 100 nsOscillator (RT pin)
fOSC Oscillator FrequencyTj=25C, RT=10kW to GND (see note *) 49 52 55 kHz
fOSCTA
Temperature Stability -40C ~105C 5 %
fOSCVREF
Voltage Stability VCC=10V~25V 0.2 1.0 %/V
DMAX Maximum Duty 75 %Frequency Jitter 4 %
Gate Drive Output (GD Pin)VOL Output Low Level VCC=15V, Isink=20mA 1 VVOH Output High Level VCC=15V, Isource=20mA 9 Vtr Rising Time Tj=25C, Load Capacitance=1nF 50 150 nstf Falling Time Tj=25C, Load Capacitance=1nF 50 150 nsVoltage Feedback (FB/PDM Pin)ISINK Short Circuit Current VFB/PDM=0V 1.5 2.2 mAVFB/PDM Open Loop Voltage FB/PDM pin open 5.5 VSCP (Short Circuit Protection)VFB/PDM SCP Trip Level VFB/PDM (SCP) 4.7 V
SCP Delay Time (See Note) fS=52kHz 75 msSoft-StarttSTART Soft-Start Time RT=10kW 10 msExternal OTP(Over Temperature Protection, TS Pin)VOTP-On OTP Enable Trigger Level 0.95 1.00 1.05 VVOTP-Reset OTP Disable Trigger Level 1.2 VITS Pull up Current Source 96 107 118 mA
Note:TheseParameters,althoughguaranteed,arenot100%testedinproduction.
"*"Suggesttolimitswitchingfrequencyunder75kHzforGreenModeoperation.
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HT7L2102
Typical Performance Characteristics
Figure 1. UVLO (on) (V) vs Temperature
Figure 3. Frequency vs Temperature
Figure 5. VFB/PDM for SCP vs Temperature
Figure 2. UVLO (off) (V) vs Temperature
Figure 4. Frequency vs VCC
Figure 6. Green Mode Frequency vs VCC
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Application Information
Operation OverviewTheHT7L2012 isahighly functionally integratedPWMcontrollerforLEDlightingandisoptimizedtorestrictEMI.Thedeviceofferadimmingprecisionoflessthan1%andhasadimmingrangeof1%to99%.Its integrated features includeGreenmode (Non-Acoustic-Noise), internalslopecompensation,highefficiencyunderdifferent loadconditionswithinawideoperatingtemperaturerangeof-40Cto85C.The devices also includes a range of protectionfunctions,SCP,OVP,UVLO,current limit,LEB,softstart,OTPforexternalthermistorsensing.Thesefeatures not only enhance system performance,but alsoensurehigh stabilityof thewholecircuitapplication even under extreme environmentalconditions suchashigh temperatureorhighEMIlevels.
Advanced Precision Oscillator for Green-Mode Switching and Non-Acoustic Noise RequirementATrimmedPrecisionGreenModeOscillator isimplementedinthedevicetoenhancetheconversionefficiencyunder light load conditions.AsFig. 7shows, theefficiencydifferencebetweenlight loadsandheavy loads is less than1%,while theaverageefficiencyisonly89.5%,thepeakefficiencyis90%.
Figure 7 HT7L2102 Efficiency Performance
between Light-Load and Heavy-Load
TheGreenModeOscillator typessuppliedbyotherPWMControllerprovidersareplaguedbyAcoustic-Noiseproblems.This isbecause,under light loadconditions, the frequencywill keep decreasingthrough theHumanAcousticRange (from20Hzto20kHz),and theseaudio frequenciesmaycreateaudiblenoiseinthetransformer.HolteksHT7L2102patentedGreenModeOscillatordesignedusinganadvancedNon-AcousticNoise structurepreventsthegenerationoffrequenciesintheaudiofrequencyband,thuseliminatinganytransformernoise.
Figure 8. Oscillator Behavior Compared with HT7L2102 and Other Green Mode PWM Controller
Frequency Jitter for EMI RestrictionEMIrestriction isaccomplishedusingaFrequencyJitterfunction,whichspreadstheenergyoverawiderfrequency range than thebandwidthmeasuredbytheEMItestequipment.AninternalFrequencyJittercircuitchangestheswitchingfrequencybetween+4%and -4%of thecentral frequencywithaperiodof4ms.
Figure 9 Frequency Jitter Function Spreads Energy Over a Period to Accomplish EMI Restraining
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Under Voltage Lockout (UVLO)AnUVLOcomparatorisimplementedin toensurethat thedevice is fullyfunctionalbefore theoutputstage is enabled.As shown inFig.10,hysteresisis provided toprevent thePWMController fromshutting down during any voltage dips whichmightoccurduringstartup.The turn-onand turn-off threshold levels are set at 16.0V and 10.0V,respectively.
Figure 10. UVLO Scheme and Start-Up Current
Current Sense and Leading-Edge Blanking (LEB)ALeading-EdgeBlankingScheme is integrated inthedevicetopreventfalsetriggeringduetofeedbackcurrent spikeswhichmay appear on theCSpin,furthereliminatingtheneedforanR-Cfilterwhichisalwaysarequirement in traditionalcurrentmodePWMControllerapplications.
Figure 11. LEB with R-C Filter Removed
Internal Slope-CompensationAn important issuewith currentmode controlstructures is instability due to Sub-HarmonicOscillationwhentheDuty-Cycle>50%.Topreventthisproblemfromoccurring,aSlope-Compensationfunct ion is a lways necessary. In t radi t ionalcurrentmodePWMController application,manyexternal components arenecessary to implementaSlope-Compensation function.However in theHT7L2102, the internal Slope-Compensationeliminates theneed for theseexternalcomponentsresultinginasimplifiedtheapplicationcircuitdesign.
Short-Circuit Protection (SCP) and Over-Load Protection (OLP)Toprotect all thedevices ina system frombeingdamagedduetooverloadorshortcircuitconditions,asmartSCPfunctionis implemented in thedevice.HerethefeedbacksystemwillforcethevoltagelooptomovetowardasaturationvalueandthenpullupthevoltageontheCOMPpin.WhenevertheVCOMPincreases to theSCPthresholdof4.7Vandremainsthereforlongerthan40mS,theprotectionschemewillactivateandthenturnoffthegateoutputtostopthepowercircuitswitching.Byusingsuchaprotectionmechanism,theaverageinputpowercanbereducedtoaverylowlevelsothatcomponenttemperatureandstresscanbecontrolledwithinsafeoperatinglevels.
Figure 12. SCP Function Behavior
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VCC Pin Over-Voltage Protection (OVP)VCCOver-VoltageProtection is integrated in thedevice toprevent componentdamagedue toovervoltage conditions on theVCCpin.TheOVP istriggeredwhenVCCreaches28Vandlastsfor100uS.ThePWMpulsesaredisabledwhenOVPisenabled.
TS Pin Over-Temperature Protection (OTP)AnOver-TemperatureProtection (OTP)function isintegrated in thedevice.ThisfunctionwithexternalthermistorsensingwilldisablethePWMcontrollerat1Vandsupportshighatemperaturealertandpreventsdamageoccurringintheapplicationcircuit.
Oscillator Frequency TuningBychoosing an appropriate value of an externalresistorbetween theRTPinandGND,a suitableoperatingfrequencycanbegenerated.TherelationshipbetweenthevalueofRTandtheoperatingfrequencyisprovidedinFigure13.
Figure 13. RT Resistor value vs Operating Frequency
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Package InformationNotethat thepackageinformationprovidedhereisforconsultationpurposesonly.Asthis informationmaybeupdatedatregularintervalsusersareremindedtoconsulttheHoltekwebsite(http://www.holtek.com.tw/english/literature/package.pdf)forthelatestversionofthepackageinformation.
8-pin SOP (150mil) Outline Dimensions
MS-012
SymbolDimensions in inch
Min. Nom. Max.A 0.228 0.244B 0.150 0.157C 0.012 0.020C' 0.188 0.197D 0.069E 0.050 F 0.004 0.010G 0.016 0.050H 0.007 0.010 0 8
SymbolDimensions in mm
Min. Nom. Max.A 5.79 6.20B 3.81 3.99C 0.30 0.51C' 4.78 5.00D 1.75E 1.27 F 0.10 0.25G 0.41 1.27H 0.18 0.25 0 8
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HT7L2102
Reel Dimensions
SOP 8N (150mil)Symbol Description Dimensions in mm
A Reel Outer Diameter 330.01.0 B Reel Inner Diameter 100.01.5 C Spindle Hole Diameter 13.0 +0.5/-0.2 D Key Slit Width 2.00.5 T1 Space Between Flange 12.8 +0.3/-0.2 T2 Reel Thickness 18.20.2
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HT7L2102
Carrier Tape Dimensions
SOP 8N (150mil)Symbol Description Dimensions in mm
W Carrier Tape Width 12.0+0.3/-0.1
P Cavity Pitch 8.00.1E Perforation Position 1.750.10F Cavity to Perforation (Width Direction) 5.50.1D Perforation Diameter 1.550.1D1 Cavity Hole Diameter 1.50 +0.25/-0.00
P0 Perforation Pitch 4.00.1P1 Cavity to Perforation (Length Direction) 2.00.1A0 Cavity Length 6.40.1B0 Cavity Width 5.20.1K0 Cavity Depth 2.10.1t Carrier Tape Thickness 0.300.05C Cover Tape Width 9.30.1
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HT7L2102
Holtek Semiconductor Inc. (Headquarters)No.3, Creation Rd. II, Science Park, Hsinchu, TaiwanTel: 886-3-563-1999Fax: 886-3-563-1189http://www.holtek.com.tw
Holtek Semiconductor Inc. (Taipei Sales Office)4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, TaiwanTel: 886-2-2655-7070Fax: 886-2-2655-7373Fax: 886-2-2655-7383 (International sales hotline)
Holtek Semiconductor (China) Inc. (Dongguan Sales Office)Building No.10, Xinzhu Court, (No.1 Headquarters), 4 Cuizhu Road, Songshan Lake, Dongguan, China 523808Tel: 86-769-2626-1300Fax: 86-769-2626-1311, 86-769-2626-1322
Holtek Semiconductor (USA), Inc. (North America Sales Office)46729 Fremont Blvd., Fremont, CA 94538, USATel: 1-510-252-9880Fax: 1-510-252-9885http://www.holtek.com
Copyright 2012 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.tw.
FeatureApplicationsGeneral DescriptionApplication CircuitsBlock DiagramPin AssignmentPin DescriptionAbsolute Maximum RatingsElectrical CharacteristicsTypical Performance CharacteristicsApplication InformationOperation OverviewAdvanced Precision Oscillator forGreen-MFrequency Jitter for EMI RestrictionUnder Voltage Lockout (UVLO)Current Sense and Leading-Edge Blanking Internal Slope-CompensationShort-Circuit Protection (SCP) andOver-LVCC Pin Over-Voltage Protection (OVP)TS Pin Over-Temperature Protection (OTP)Oscillator Frequency Tuning
Package Information8-pin SOP (150mil) Outline DimensionsReel DimensionsCarrier Tape Dimensions