Product Sample & Technical Tools & Support & Folder Buy Documents Software Community UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 UCCx81xA BiCMOS Power Factor Preregulator 1 Features 3 Description • ControlsBoostPreregulatortoNear-UnityPower The UCC3817A and the UCC3818A family provides 1 all the functions necessary for active power factor Factor corrected preregulators. The controller achieves near • LimitsLineDistortion unity power factor by shaping the ac input line current • WorldWideLineOperation waveform to correspond to that of the ac input line • OvervoltageProtection voltage. Average current mode control maintains stable,lowdistortionsinusoidallinecurrent. • AccuratePowerLimiting DesignedinTexasInstrument'sBiCMOSprocess,the • AverageCurrentModeControl UCC3817A/UCC3818A offers new features such as • ImprovedNoiseImmunity lower start-up current, lower power dissipation, • ImprovedFeed-ForwardLineRegulation overvoltage protection, a shunt UVLO detect circuitry, • LeadingEdgeModulation a leading-edge modulation technique to reduce ripple current in the bulk capacitor and an improved, low- • 150-µATypicalStart-UpCurrent offset (±2 mV) current amplifier to reduce distortion at • Low-PowerBiCMOSOperation lightloadconditions. • 12-Vto17-VOperation DeviceInformation(1) • FrequencyRangeof6kHzto220kHz PARTNUMBER PACKAGE BODYSIZE(NOM) 2 Applications SOIC(16) 4.90mm×3.91mm • PCPower UCCx81xA PDIP(16) 19.30mm×6.35mm TSSOP(16) 5.00mm×4.40mm • ConsumerElectronics • Lighting (1) For all available packages, see the orderable addendum at theendofthedatasheet. • IndustrialPowerSupplies • IEC6100-3-2CompliantSuppliesLessThan 300W BlockDiagram VCC 15 OVP/EN 10 16 V (FOR UCC3817A ONLY) 7.5 V 9 VREF REFERENCE SS 13 1.9 V (cid:237) ENABLE UVLO 16 V/10 V (UCC3817A) VAOUT 7 + 10.5 V/10 V (UCC3818A) ZERO POWER 0.33 V (cid:237) VCC VOLTAGE VSENSE 11 (cid:237) ERROR AMP + CURRENT 8.0 V + OVP 7.5 V + X AMP (cid:237) ÷X MULT (cid:237) (cid:237) PWM 16 DRVOUT + S Q VFF 8 X2 + PWM OSC LATCH R R MIRROR CLK 2:1 1 GND CLK IAC 6 OSCILLATOR (cid:237) 2 PKLMT + MOUT 5 4 3 12 14 CAI CAOUT RT CT Copyright © 2016, Texas Instruments Incorporated 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com Table of Contents 1 Features.................................................................. 1 9.4 DeviceFunctionalModes........................................12 2 Applications........................................................... 1 10 ApplicationandImplementation........................ 14 3 Description............................................................. 1 10.1 ApplicationInformation..........................................14 4 Revision.................................................................. 2 10.2 TypicalApplication................................................15 5 Description(Continued)........................................ 3 11 PowerSupplyRecommendations..................... 25 6 DeviceComparisonTables................................... 3 12 Layout................................................................... 25 12.1 LayoutGuidelines.................................................25 7 PinConfigurationandFunctions......................... 4 12.2 LayoutExample....................................................25 8 Specifications......................................................... 5 13 DeviceandDocumentationSupport................. 26 8.1 AbsoluteMaximumRatings......................................5 13.1 DocumentationSupport........................................26 8.2 ESDRatings..............................................................5 13.2 RelatedLinks........................................................26 8.3 RecommendedOperatingConditions.......................5 13.3 ReceivingNotificationofDocumentationUpdates26 8.4 ThermalInformation..................................................6 13.4 CommunityResource............................................26 8.5 ElectricalCharacteristics...........................................6 13.5 Trademarks...........................................................26 8.6 TypicalCharacteristics..............................................8 13.6 ElectrostaticDischargeCaution............................26 9 DetailedDescription.............................................. 9 13.7 Glossary................................................................26 9.1 Overview...................................................................9 14 Mechanical,Packaging,andOrderable 9.2 FunctionalBlockDiagram.........................................9 Information........................................................... 27 9.3 FeatureDescription...................................................9 4 Revision NOTE:Pagenumbersforpreviousrevisionsmaydifferfrompagenumbersinthecurrentversion. ChangesfromRevisionC(November2011)toRevisionD Page • AddedESDRatingstable,FeatureDescriptionsection,DeviceFunctionalModes,ApplicationandImplementation section,PowerSupplyRecommendationssection,Layoutsection,DeviceandDocumentationSupportsection,and Mechanical,Packaging,andOrderableInformationsection ................................................................................................. 1 • ChangedtheR andR thermalvaluesforallpackages............................................................................................. 6 θJA θJC(top) • CombinedtheElectricalCharacteristicstables...................................................................................................................... 6 2 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 5 Description (Continued) The UCC3817A/18A family of PFC Controllers is directly pin for pin compatible with the UCC3817/18 family of devices. Only the output stage of UCC3817A family has been modified to allow use of a smaller external gate drive resistor values. For some power supply designs where an adequately high enough gate drive resistor can not be used, the UCC3817A/18A family offers a more robust output stage at the cost of increasing the internal gate resistances. The gate drive of the UC3817A/18A family however remains strong at ±1.2 A of peak current capability. UCC3817A offers an on-chip shunt regulator with low start-up current, suitable for applications utilizing a bootstrap supply. UCC3818A is intended for applications with a fixed supply (VCC). Both devices are available in the16-pinD,NandPWpackages. 6 Device Comparison Tables Table1.AvailableOptions PACKAGEDEVICES SOIC(D)PACKAGE(1) PDIP(N)PACKAGE TSSOP(PW)PACKAGE(1) T =T A J TURNON TURNON TURNON TURNON TURNON TURNON THRESHOLD THRESHOLD THRESHOLD THRESHOLD THRESHOLD THRESHOLD 16V 10.2V 16V 10.2V 16V 10.2V –40°Cto85°C UCC2817AD UCC2818AD UCC2817AN UCC2818AN UCC2817APW UCC2818APW 0°Cto70°C UCC3817AD UCC3818AD UCC3817AN UCC3818AN UCC3817APW UCC3818APW (1) TheDandPWpackagesareavailabletapedandreeled.AddRsuffixtothedevicetype(e.g.UCC3817ADR)toorderquantitiesof 2,500devicesperreel(Dpackage)and2,000devicesperreel(forPWpackage).Bulkquantitiesare40units(Dpackage)and90units (PWpackage)pertube. Table2.RelatedProducts DEVICE DESCRIPTION CONTROLMETHOD TYPICALPOWERLEVEL UC3854 PFCcontroller ACM(1) 200Wto2kW+ UC3854A/B ImprovedPFCcontroller ACM(1) 200Wto2kW+ UC3855A/B HighperformancesoftswitchingPFCcontroller ACM(1) 400Wto2kW+ UCC38050/1 TransitionmodePFCcontroller CRM(2) 50Wto400W UCC3819 TrackingboostPFCcontroller ACM(1) 75Wto2kW+ UCC28510/11/12/13 AdvancedPFC+PWMcombocontroller ACM(1) 75Wto1kW+ UCC28514/15/16/17 AdvancedPFC+PWMcombocontroller ACM(1) 75Wto1kW+ (1) Averagecurrentmode (2) Criticalconductionmode Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 7 Pin Configuration and Functions D,N,andPWPackages 16-PinSOIC,PDIP,andTSSOP TopView GND 1 16 DRVOUT PKLMT 2 15 VCC CAOUT 3 14 CT CAI 4 13 SS MOUT 5 12 RT IAC 6 11 SSENSE VAOUT 7 10 OVP/EN VFF 8 9 VREF Not to scale PinFunctions PIN I/O DESCRIPTION NO. NAME 4 CAI I Currentamplifiernoninvertinginput 3 CAOUT O Currentamplifieroutput 14 CT I Oscillatortimingcapacitor 16 DRVOUT O Gatedrive 1 GND — Ground 6 IAC I Currentproportionaltoinputvoltage 5 MOUT I/O Multiplieroutputandcurrentamplifierinvertinginput 10 OVP/EN I Overvoltage/enable 2 PKLMT I PFCpeakcurrentlimit 12 RT I Oscillatorchargingcurrent 13 SS I Soft-start 7 VAOUT O Voltageamplifieroutput 15 VCC I Positivesupplyvoltage 8 VFF I Feed-forwardvoltage 11 SSENSE I Voltageamplifierinvertinginput 9 VREF O Voltagereferenceoutput 4 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 8 Specifications 8.1 Absolute Maximum Ratings overoperatingfree-airtemperaturerange(unlessotherwisenoted)(1) MIN MAX UNIT SupplyvoltageVCC 18 V SupplycurrentICC 20 mA Gatedrivecurrent,continuous 0.2 A Gatedrivecurrent 1.2 A Inputvoltage,CAI,MOUT,SS 8 V Inputvoltage,PKLMT 5 V Inputvoltage,VSENSE,OVP/EN 10 V Inputcurrent,RT,IAC,PKLMT 10 mA Inputcurrent,VCC(noswitching) 20 mA Maximumnegativevoltage,DRVOUT,PKLMT,MOUT –0.5 V Powerdissipation 1 W Leadtemperature,T (soldering,10seconds) 300 °C sol Powerdissipation 1 W Junctiontemperature,T –55 150 °C J Storagetemperature,T –65 150 °C stg (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. 8.2 ESD Ratings VALUE UNIT Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1) ±2000 V(ESD) Electrostaticdischarge Charged-devicemodel(CDM),perJEDECspecificationJESD22- V C101(2) ±1500 (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. (2) JEDECdocumentJEP157statesthat250-VCDMallowssafemanufacturingwithastandardESDcontrolprocess. 8.3 Recommended Operating Conditions overoperatingfree-airtemperaturerange(unlessotherwisenoted) MIN NOM MAX UNIT VCC Inputvoltage 12 18 V VSENSE Inputsensevoltage 7.5 10 V Inputcurrentforoscillator 1.36 10 mA Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 8.4 Thermal Information UCCx81xA THERMALMETRIC(1) D(SOIC) N(PDIP) PW(TSSOP) UNIT 16PINS 16PINS 16PINS R Junction-to-ambientthermalresistance 73.9 49.3 98.9 °C/W θJA R Junction-to-case(top)thermalresistance 33.5 38.9 30.2 °C/W θJC(top) R Junction-to-boardthermalresistance 31.4 29.4 44.8 °C/W θJB ψ Junction-to-topcharacterizationparameter 5.8 18.9 1.9 °C/W JT ψ Junction-to-boardcharacterizationparameter 31.1 29.2 44.1 °C/W JB (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplication report. 8.5 Electrical Characteristics T =0°Cto70°CfortheUCC3817AandT =–40°Cto85°CfortheUCC2817A,T =T,VCC=12V,R =22kΩ,C =270 A A A J T T pF,(unlessotherwisenoted) PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SUPPLYCURRENTSECTION Supplycurrent,OFF VCC=(VCCturnonthreshold–0.3V) 150 300 µA Supplycurrent,ON VCC=12V,NoloadonDRVOUT 2 4 6 mA UVLOSECTION VCCturnonthreshold(UCCx817) 15.4 16 16.6 V VCCturnoffthreshold(UCCx817) 9.4 9.7 V UVLOhysteresis(UCCx817) 5.8 6.3 V Maximumshuntvoltage(UCCx817) I =10mA 15.4 17 17.5 V VCC VCCturnonthreshold(UCCx818) 9.7 10.2 10.8 V VCCturnoffthreshold(UCCx818) 9.4 9.7 V UVLOhysteresis(UCCx818) 0.3 0.5 V VOLTAGEAMPLIFIERSECTION T =0°Cto70°C 7.387 7.5 7.613 A Inputvoltage V T =-–40°Cto85°C 7.369 7.5 7.631 A V biascurrent V =V ,VAOUT=2.5V 50 200 nA SENSE SENSE REF Open-loopgain VAOUT=2Vto5V 50 90 dB High-leveloutputvoltage I =–150µA 5.3 5.5 5.6 V L Low-leveloutputvoltage I =150µA 0 50 150 mV L OVERVOLTAGEPROTECTIONANDENABLESECTION VREF VREF VREF Overvoltagereference V +0.48 +0.50 +0.52 Hysteresis 300 500 600 mV Enablethreshold 1.7 1.9 2.1 V Enablehysteresis 0.1 0. 0.3 V CURRENTAMPLIFIERSECTION Inputoffsetvoltage V =0V,V =3V –3.5 0 2.5 mV CM CAOUT Inputbiascurrent V =0V,V =3V –50 –100 nA CM CAOUT Inputoffsetcurrent V =0V,V =3V 25 100 nA CM CAOUT Openloopgain V =0V,V =2Vto5V 90 dB CM CAOUT Common-modeoutputvoltage V =0Vto1.5V,V =3V 60 80 dB CM CAOUT High-leveloutputvoltage I =–120mA 5.6 6.5 6.8 VV L Low-leveloutputvoltage I =1mA 0.1 0.2 0.5 MHz L Gainbandwidthproduct See (1) 2.5 (1) Ensuredbydesign,notproductiontested. 6 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 Electrical Characteristics (continued) T =0°Cto70°CfortheUCC3817AandT =–40°Cto85°CfortheUCC2817A,T =T,VCC=12V,R =22kΩ,C =270 A A A J T T pF,(unlessotherwisenoted) PARAMETER TESTCONDITIONS MIN TYP MAX UNIT VOLTAGEREFERENCESECTION T =0°Cto70°C 7.387 7.5 7.613 A Inputvoltage V T =-–40°Cto85°C 7.369 7.5 7.631 A Loadregulation I =1mAto2mA 0 10 mV REF Lineregulation VCC=10.8to15V(2) 0 10 mV Short-circuitcurrent V =0V –20 –25 –50 mA REF OSCILLATORSECTION Initialaccuracy T =25°C 85 100 115 kHz A Voltagestability VCC=10.8to15V –1% 1% Totalvariation Line,temp 80 120 kHz Ramppeakvoltage 4.5 5 5.5 V Rampamplitudevoltage(peaktopeak) 3.5 4 4.5 V PEAKCURRENTLIMITSECTION PKLMTreferencevoltage –15 15 mV PKLMTpropagationdelay 150 350 500 ns MULTIPLIERSECTION I ,highline,lowpoweroutput MOUT I =500µA,V =4.7V,VAOUT=1.25V 0 –6 –20 current,(0°Cto85°C) AC FF I ,highline,lowpoweroutput MOUT I =500µA,V =4.7V,VAOUT=1.25V 0 –6 –23 current,(–40°Cto85°C) AC FF I ,highline,lowpoweroutput cMuOrrUeTnt IAC=500µA,VFF=4.7V,VAOUT=5V –70 –90 –105 µA I ,lowline,lowpoweroutputcurrent I =150µA,V =1.4V,VAOUT=1.25V –10 –19 –50 MOUT AC FF I ,lowline,highpoweroutput MOUT I =150µA,V =1.4V,VAOUT=5V –268 –300 –345 current AC FF I ,IAClimitedoutputcurrent I =150µA,V =1.3V,VAOUT=5V –250 –300 –400 MOUT AC FF Gainconstant(K) I =150µA,V =1.3V,VAOUT=2.5V 0.5 1 1.5 1/V AC FF I =150µA,V =1.4V,VAOUT=0.25V 0 –2 AC FF I ,zerocurrent µA MOUT I =500µA,V =4.7V,VAOUT=0.25V 0 –2 AC FF I ,zerocurrent,(0°Cto85°C) I =500µA,V =4.7V,VAOUT=0.5V 0 –3 MOUT AC FF µA I ,zerocurrent,(–40°Cto85°C) I =500µA,V =4.7V,VAOUT=0.5V 0 –3.5 MOUT AC FF Powerlimit(I xV ) I =150µA,V =1.4V,VAOUT=5V –375 –420 –485 µW MOUT FF AC FF FEED-FORWARDSECTION VFFoutputcurrent I =300µA –140 –150 –160 µA AC SOFTSTARTSECTION SSchargecurrent –6 –10 –16 µA GATEDRIVERSECTION Pullupresistance I =–100mAto–200mA 9 12 O Ω Pulldownresistance I =100mA 4 10 O Outputrisetime C =1nF,R =10Ω,V =0.7Vto9V 25 50 L L DRVOUT ns Outputfalltime C =1nF,R =10Ω,V =9Vto0.7V 10 50 L L DRVOUT Maximumdutycycle 93% 95% 99% Minimumcontrolleddutycycle At100kHz 2% ZEROPOWERSECTION Zeropowercomparatorthreshold MeasuredonVAOUT 0.2 0.33 0.5 V (2) ReferencevariationforV <10.8VisshowninFigure12. CC Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 8.6 Typical Characteristics 100 1.2 VIN = 85 V 1.12 VIN = 175 V VIN = 265 V 95 1.04 0.96 %) 90 or 0.88 y ( act cienc wer F 0.8 Effi 85 Po 0.72 0.64 80 0.56 VIN = 85 V 0.48 VIN = 175 V VIN = 265 V 75 0.4 25 50 75 100 125 150 175 200 225 250 25 50 75 100 125 150 175 200 225 250 275 Output Power Output Power (W) D001 D001 Figure1.EfficiencyvsOutputPower Figure2.PowerFactorvsOutputPower 8 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 9 Detailed Description 9.1 Overview The UCC3817A and the UCC3818A family of products provides PFC controllers all the necessary functions for achievingnearunityPFC. The UCC3817A and UCC3818A, while being pin-compatible with other industry controllers providing similar functionality, offer many feature enhancements and tighter specifications, leading to an overall reduction in systemimplementationcost. The system performance is enhanced by incorporating many innovative features such as average current-mode control which maintains stable noise immune low distortion sinusoidal current. Also, the IC features a leading edge modulation which when synchronized properly with a second stage DC-DC converter can reduce the ripple currentontheoutputcapacitortherebyincreasingtheoveralllifetimeofthepowersupply. In addition to these features, the key difference between the UCC281xA and the UCC381xA is that the UCC2817A can work over the extended temperature range of –40 to 85°C as opposed to 0 to 70°C in the case oftheUCC3817A. 9.2 Functional Block Diagram VCC 15 OVP/EN 10 16 V (FOR UCC3817A ONLY) 7.5 V 9 VREF REFERENCE SS 13 1.9 V (cid:237) ENABLE UVLO 16 V/10 V (UCC3817A) VAOUT 7 + 10.5 V/10 V (UCC3818A) ZERO POWER 0.33 V (cid:237) VCC VOLTAGE VSENSE 11 (cid:237) ERROR AMP + CURRENT 8.0 V + OVP 7.5 V + X AMP (cid:237) ÷X MULT (cid:237) (cid:237) PWM 16 DRVOUT + S Q VFF 8 X2 + PWM OSC LATCH R R MIRROR CLK 2:1 1 GND CLK IAC 6 OSCILLATOR (cid:237) 2 PKLMT + MOUT 5 4 3 12 14 CAI CAOUT RT CT Copyright © 2016, Texas Instruments Incorporated 9.3 Feature Description 9.3.1 ReferenceSectionandErrorAmplifier Thereferenceisahighlyaccurate7-Vreferencewithanaccuracyofthereferenceis1.5%. Theerroramplifierisaclassicvoltageerroramplifierandhasashortcircuitcurrentcapabilityof20mA. 9.3.2 ZeroPowerBlock When the output of the zero power comparator goes below 2.3 V, the zero power comparator latches the gate drivesignallow. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com Feature Description (continued) 9.3.3 Multiplier The multiplier has 3 inputs. The inputs to the multiplier are VAOUT, the voltage amplifier error signal, IIAC, a representationoftheinputrectifiedAClinevoltage,andaninputvoltagefeedforwardsignal,VVFF. ThemultiplierperformsthecalculationinEquation1. IMOUNT=IAC×(VVAOUT–1)/(K×VVff2) where • K=1/V (1) As the multiplier output is a current, this is a high-impedance input so the amplifier can be configured as a differential amplifier. This configuration improves noise immunity and allows for the leading-edge modulation operation. 9.3.4 OutputOvervoltageProtection When the output voltage exceeds the OVP threshold, the IC stops switching. The OVP reference is at 1.07%. Thereisalsoa500mVofhysteresisatthepin. 9.3.5 PinDescriptions 9.3.5.1 CAI Place a resistor between this pin and the GND side of current sense resistor. This input and the inverting input (MOUT)remainfunctionaldowntoandbelowGND. 9.3.5.2 CAOUT This is the output of a wide bandwidth operational amplifier that senses line current and commands the PFC pulse-width modulator (PWM) to force the correct duty cycle. Compensation components are placed between CAOUTandMOUT. 9.3.5.3 CT AcapacitorfromCTtoGNDsetsthePWMoscillatorfrequencyaccordingtoEquation2: § 0.6 • f |¤ ‚ 'RTuCT„ (2) TheleadfromtheoscillatortimingcapacitortoGNDshouldbeasshortanddirectaspossible. 9.3.5.4 DRVOUT The output drive for the boost switch is a totem-pole MOSFET gate driver on DRVOUT. To avoid the excessive overshoot of the DRVOUT while driving a capacitive load, a series gate current-limiting/damping resistor is recommended to prevent interaction between the gate impedance and the output driver. The value of the series gate resistor is based on the pulldown resistance (R which is 4 Ω typical), the maximum VCC voltage pulldown (VCC), and the required maximum gate drive current (I ). Using Equation 3, a series gate resistance of MAX resistance 11 Ω would be required for a maximum VCC voltage of 18 V and for 1.2 A of maximum sink current. Thesourcecurrentwillbelimitedtoapproximately900mA(basedontheRpullupof9-Ωtypical). VCC(cid:16)(cid:11)IMAXuRpulldown(cid:12) RGATE IMAX (3) 9.3.5.5 GND All voltages measured with respect to ground. VCC and REF should be bypassed directly to GND with a 0.1-µF orlargerceramiccapacitor. 10 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 Feature Description (continued) 9.3.5.6 IAC This input to the analog multiplier is a current proportional to instantaneous line voltage. The multiplier is tailored for very low distortion from this current input (I ) to multiplier output. The recommended maximum I is IAC IAC 500µA. 9.3.5.7 MOUT The output of the analog multiplier and the inverting input of the current amplifier are connected together at MOUT. As the multiplier output is a current, this is a high-impedance input so the amplifier can be configured as a differential amplifier. This configuration improves noise immunity and allows for the leading-edge modulation operation.Themultiplieroutputcurrentislimitedto(2 × I ).ThemultiplieroutputcurrentisgivenbyEquation4: IAC IMOUT IIACu(VVAOUT(cid:16)1) VVFF2uK (4) 1 K = V where isthemultipliergainconstant. 9.3.5.8 OVP/EN A window comparator input that disables the output driver if the boost output voltage is a programmed level abovethenominalordisablesboththePFCoutputdriverandresetsSSifpulledbelow1.9V(typical). 9.3.5.9 PKLMT The threshold for peak limit is 0 V. Use a resistor divider from the negative side of the current sense resistor to VREF to level shift this signal to a voltage level defined by the value of the sense resistor and the peak current limit.PeakcurrentlimitisreachedwhenPKLMTvoltagefallsbelow0V. 9.3.5.10 RT A resistor from RT to GND is used to program oscillator charging current. TI recommends a resistor between 10kΩand100kΩ.Nominalvoltageonthispinis3V. 9.3.5.11 SS VSS is discharged for VVCC low conditions. When enabled, SS charges an external capacitor with a current source. This voltage is used as the voltage error signal during start-up, enabling the PWM duty cycle to increase slowly. In the event of a V dropout, the OVP/EN is forced below 1.9 V (typ), SS quickly discharges to disable VCC thePWM. NOTE In an open-loop test circuit, grounding the SS pin does not ensure 0% duty cycle. See the applicationsectionfordetails. 9.3.5.12 VAOUT This is the output of the operational amplifier that regulates output voltage. The voltage amplifier output is internallylimitedtoapproximately5.5Vtopreventovershoot. 9.3.5.13 VCC Connect to a stable source of at least 20 mA from 10 V to 17 V for normal operation. Bypass VCC directly to GND to absorb supply current spikes required to charge external MOSFET gate capacitances. To prevent inadequate gate drive signals, the output devices are inhibited unless V exceeds the upper undervoltage VCC lockoutvoltagethresholdandremainsabovethelowerthreshold. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com Feature Description (continued) 9.3.5.14 VFF The RMS voltage signal generated at this pin by mirroring 1/2 of the I into a single pole external filter. At low IAC line,theVFFvoltageshouldbe1.4V. 9.3.5.15 VSENSE This is normally connected to a compensation network and to the boost converter output through a divider network. 9.3.5.16 VREF VREF is the output of an accurate 7.5-V voltage reference. This output is capable of delivering 20 mA to peripheral circuitry and is internally short-circuit current limited. VREF is disabled and remains at 0 V when V VCC is below the UVLO threshold. Bypass VREF to GND with a 0.1-µF or larger ceramic capacitor for best stability. SeeFigure12andFigure13forVREFlineandloadregulationcharacteristics. 9.4 Device Functional Modes 9.4.1 TransitionModeControl The boost converter, the most common topology used for power factor correction, can operate in two modes: continuous conduction code (CCM) and discontinuous conduction mode (DCM). Transition mode control, also referred to as critical conduction mode (CRM) or boundary conduction mode, maintains the converter at the boundarybetweenCCMandDCMbyadjustingtheswitchingfrequency. The CRM converter typically uses a variation of hysteretic control, with the lower boundary equal to zero current. It is a variable frequency control technique that has inherently stable input current control while eliminating reverse recovery rectifier losses. As shown in Figure 3, the switch current is compared to the reference signal (output of the multiplier) directly. This control method has the advantage of simple implementation and good powerfactorcorrection. L VAC D Q Load C R IAC GateDriver IAC ZCD S Q Logic X÷ MULT IMO + R VEA X + UDG−02124 VREF Figure3. BasicBlockDiagramofCRMBoostPFC 12 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 Device Functional Modes (continued) The power stage equations and the transfer functions of the CRM are the same as the CCM. However, implementations of the control functions are different. Transition mode forces the inductor current to operate just at the border of CCM and DCM. The current profile is also different, and affects the component power loss and filtering requirements. The peak current in the CRM boost is twice the amplitude of CCM, leading to higher conduction losses. The peak-to-peak ripple is twice the average current, which affects MOSFET switching losses andmagneticsaclosses. IAVERAGE (a) CCM IPEAK IAVERAGE (b) DCM IPEAK IAVERAGE Note:OperatingFrequency>>120Hz (C) CRM UDG−02123 Figure4. PFCInductorCurrentProfiles For low to medium power applications up to approximately 300 W, the CRM boost has an advantage in losses. The filtering requirement is not severe, and therefore is not a disadvantage. For medium to higher power applications, where the input filter requirements dominate the size of the magnetics, the CCM boost is a good choice due to lower peak currents (which reduces conduction losses) and lower ripple current (which reduces filter requirements). The main tradeoff in using CRM boost is lower losses due to no reverse recovery in the boostdiodevshigherrippleandpeakcurrents. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 10 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validateandtesttheirdesignimplementationtoconfirmsystemfunctionality. 10.1 Application Information The UCC3817A is a BiCMOS average current mode boost controller for high power factor, high efficiency preregulator power supplies. Figure 5 shows the UCC3817A in a 250-W PFC preregulator circuit. Off-line switching power converters normally have an input current that is not sinusoidal. The input current waveform has a high harmonic content because current is drawn in pulses at the peaks of the input voltage waveform. An active power factor correction circuit programs the input current to follow the line voltage, forcing the converter to look like a resistive load to the line. A resistive load has 05 phase displacement between the current and voltage waveforms. Power factor can be defined in terms of the phase angle between two sinusoidal waveforms of the samefrequency: PF cos4 (5) Therefore, a purely resistive load would have a power factor of 1. In practice, power factors of 0.999 with THD (total harmonic distortion) of less than 3% are possible with a well-designed circuit. See the following guidelines fordesigningPFCboostconvertersusingtheUCC3817A. NOTE Schottky diodes, D5 and D6, are required to protect the PFC controller from electrical over stressduringsystempowerup. 14 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 10.2 Typical Application R16 C10 C11 100 (cid:159) 1µF 1µF VCC R15 D7 24 k(cid:13) D8 R21 R13 383 k(cid:13) 383 k(cid:13) L1 IAC 1mH R241 8k(cid:13) D1 VO 8A, 600V F1 AC2 + D2 VLINE 1C.514µF 0.C4173µF 6A, 600V 85(cid:237)270 VAC 400V D3 600V Q1 VOUT AC1 R14 IRFP450 2C201µ2F 385V(cid:237)DC 0.25 (cid:159) 450V 6A 600V 3W (cid:237) R17 UCC3817A 20 (cid:159) R2 1k2(cid:13) R4.902 k(cid:13) R4.1002 k(cid:13) 1 GND DRVOUT 16 D4 VCC C3 2 PKLIMIT 1µF CER R11 D5 VCC 15 10 k(cid:13) 3 CAOUT C2 100 µF AI EI 4 CAI C1 560 pF VREF 5 MOUT CT 14 R8 12 k(cid:13) C9 1.2 nF C4 0.01 µF 6 IAC SS 13 C8 270 pF R1 12 k(cid:13) D6 C7 150 nF RT 12 R1070 k(cid:13) C15 2.2 µF VSENSE 11 R2 R19 VO 7 VAOUT R3 20 k(cid:13) 499 k(cid:13) 499 k(cid:13) C6 2.2 µF R20 R4 8 VFF 274 k(cid:13) 249 k(cid:13) OVP/EN 10 R6 30 k(cid:13) C5 1 µF R5 10 k(cid:13) VREF 9 VREF Copyright © 2016, Texas Instruments Incorporated Figure5. TypicalApplicationCircuit 10.2.1 DesignRequirements Table3liststheparametersforthisapplication. Table3.DesignParameters PARAMETER TESTCONDITIONS MIN TYP MAX UNIT VIN InputRMSvoltage 85 270 V Inputfrequency 50/60 Hz VOUT OutputVoltage 385 420 V POUT OutputPower 250 W HoldupTime Alllineandloadconditions 16 ms Efficiency Efficiencyat85Vrms,100%Load 91% THDatLowLine 85Vrms=100%Load 5% THDatHighLine 265Vrms,100%Load 15% Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 10.2.2 DetailedDesignProcedure 10.2.2.1 PowerStage 10.2.2.1.1 LBOOST TheboostinductorvalueisdeterminedbyEquation6: (cid:11)VIN(min)uD(cid:12) LBOOST (cid:11)’Iufs(cid:12) (6) where D is the duty cycle, DI is the inductor ripple current and fS is the switching frequency. For the example circuit a switching frequency of 100 kHz, a ripple current of 875 mA, a maximum duty cycle of 0.688 and a minimum input voltage of 85 VRMS gives us a boost inductor value of about 1 mH. The values used in this equationareatthepeakoflowline,wheretheinductorcurrentanditsrippleareatamaximum. 10.2.2.1.2 C OUT Two main criteria, the capacitance and the voltage rating, dictate the selection of the output capacitor. The value of capacitance is determined by the holdup time required for supporting the load after input ac voltage is removed. Holdup is the amount of time that the output stays in regulation after the input has been removed. For this circuit, the desired holdup time is approximately 16 ms. Expressing the capacitor value in terms of output power,outputvoltage,andholduptimegivesEquation7: (cid:11)2uPOUTu’t(cid:12) COUT (cid:11)VOUT2(cid:16)VOUT(min)2(cid:12) (7) In practice, the calculated minimum capacitor value may be inadequate because output ripple voltage specifications limit the amount of allowable output capacitor ESR. Attaining a sufficiently low value of ESR often necessitates the use of a much larger capacitor value than calculated. The amount of output capacitor ESR allowedcanbedeterminedbydividingthemaximumspecifiedoutputripplevoltagebytheinductorripplecurrent. In this design holdup time was the dominant determining factor and a 220-µF, 450-V capacitor was chosen for theoutputvoltagelevelof385VDCat250W. 10.2.2.1.3 PowerSwitchSelection As in any power supply design, tradeoffs between performance, cost and size have to be made. When selecting a power switch, it can be useful to calculate the total power dissipation in the switch for several different devices at the switching frequencies being considered for the converter. Total power dissipation in the switch is the sum of switching loss and conduction loss. Switching losses are the combination of the gate charge loss, C loss OSS andturnonandturnofflosses,asshowninEquation8,Equation9,andEquation10. P =Q ´V ´ f GATE GATE GATE S (8) 1 P = ´C ´V2 ´ f COSS 2 OSS OFF S (9) 1 P +P = ´V ´I (t +t )´ f ON OFF 2 OFF L ON OFF S where • Q isthetotalgatecharge GATE • V isthegatedrivevoltage GATE • f istheclockfrequency S • C isthedrainsourcecapacitanceoftheMOSFET OSS • I isthepeakinductorcurrent L • t andt aretheswitchingtimes(estimatedusingdeviceparametersR ON OFF GATE • Q andV )andV isthevoltageacrosstheswitchduringtheofftime,inthiscaseV =V (10) GD TH OFF OFF OUT Conduction loss is calculated with Equation 11 as the product of the R of the switch (at the worst case DS(on) junctiontemperature)andthesquareofRMScurrent: 16 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 P = R ´K´I2 COND DS(on) RMS where • Kisthetemperaturefactorfoundinthemanufacturer'sR vs.junctiontemperaturecurves (11) DS(on) Calculating these losses and plotting against frequency gives a curve that enables the designer to determine either which manufacturer's device has the best performance at the desired switching frequency, or which switching frequency has the least total loss for a particular power switch. For this design example an IRFP450 HEXFET from International Rectifier was chosen because of its low R and its V rating. The IRFP450's DS(on) DSS R of 0.4 Ω and the maximum V of 500 V made it an ideal choice. An excellent review of this procedure DS(on) DSS can be found in the Unitrode Power Supply Design Seminar SEM1200, Topic 6, Design Review: 140 W, [Multiple OutputHighDensityDC/DCConverter]. 10.2.2.2 SoftStart The soft-start circuitry is used to prevent overshoot of the output voltage during start-up. This is accomplished by bringing up the voltage amplifier's output (V ) slowly which allows for the PWM duty cycle to increase slowly. VAOUT Usethefollowingequationtoselectacapacitorforthesoft-startpin. Inthisexamplet isequalto7.5ms,whichwouldyieldaC of10nF. DELAY SS 10PAutDELAY CSS 7.5V (12) Inanopen-looptestcircuit,shortingthesoft-startpintogrounddoesnotensure0%dutycycle.Thisisduetothe currentamplifiersinputoffsetvoltage,whichcouldforcethecurrentamplifieroutputhighorlowdependingonthe polarity of the offset voltage. However, in the typical application there is sufficient amount of inrush and bias currenttoovercomethecurrentamplifier'soffsetvoltage. 10.2.2.3 Multiplier The output of the multiplier of the UCC3817A is a signal representing the desired input line current. It is an input to the current amplifier, which programs the current loop to control the input current to give high power factor operation. As such, the proper functioning of the multiplier is key to the success of the design. The inputs to the multiplier are VAOUT, the voltage amplifier error signal, IIAC, a representation of the input rectified ac line voltage, and an input voltage feedforward signal, V . The output of the multiplier, I , can be expressed as VFF MOUT showninEquation13. (cid:11)VVAOUT(cid:16)1(cid:12) IMOUT IIACu KuVVFF2 where • Kisaconstanttypicallyequalto1/V. (13) The Electrical Characteristics table covers all the required operating conditions for designing with the multiplier. Additionally, curves in Figure 14, Figure 15, and Figure 16 provide typical multiplier characteristics over its entire operatingrange. The I signal is obtained through a high-value resistor connected between the rectified ac line and the IAC pin IAC of the UCC3817A and UCC3818A. This resistor (R ) is sized to give the maximum I current at high line. For IAC IAC the UCC3817A and UCC3818A the maximum I current is about 500 mA. A higher current than this can drive IAC the multiplier out of its linear range. A smaller current level is functional, but noise can become an issue, especiallyatlowinputline.Assumingauniversallineoperationof85V to265V givesaR valueof750 RMS RMS IAC kΩ. Because of voltage rating constraints of standard 1/4-W resistor, use a combination of lower value resistors connected in series to give the required resistance and distribute the high voltage amongst the resistors. For this designexampletwo383-kΩresistorswereusedinseries. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com The current into the IAC pin is mirrored internally to the VFF pin where it is filtered to produce a voltage feed forward signal proportional to line voltage. The VFF voltage is used to keep the power stage gain constant; and to provide input power limiting. See Texas Instruments application note Unitrode - UC3854A/B and UC3855A/B Provide Power Limiting With Sinusoidal Input Current for PFC Front Ends (SLUA196) for a detailed explanation on how the VFF pin provides power limiting. Equation 14 can be used to size the VFF resistor (R ) to provide VFF power limiting where V is the minimum RMS input voltage and R is the total resistance connected IN(min) IAC betweentheIACpinandtherectifiedlinevoltage. 1.4V RVFF VIN(min)u0.9 |30k: 2uRIAC (14) Because the VFF voltage is generated from line voltage it needs to be adequately filtered to reduce total harmonic distortion caused by the 120 Hz rectified line voltage. Refer to the Unitrode Power Supply Design Seminar, SEM-700 Topic 7, [Optimizing the Design of a High Power Factor Preregulator.] A single pole filter was adequate for this design. Assuming that an allocation of 1.5% total harmonic distortion from this input is allowed, and that the second harmonic ripple is 66% of the input ac line voltage, the amount of attenuation required by thisfilteris: 1.5% 0.022 66% (15) Witharipplefrequency(f )of120Hzandanattenuationof0.022requiresthatthepoleofthefilter(f )beplaced R P at: fP 120Hzu0.022|2.6Hz (16) Equation17canbeusedtoselectthefiltercapacitor(C )requiredtoproducethedesiredlowpassfilter. VFF 1 CVFF |2.2PF 2uSuRVFFufP (17) The R resistor is sized to match the maximum current through the sense resistor to the maximum multiplier MOUT current.Themaximummultipliercurrent,orI ,canbedeterminedbyEquation18: MOUT(max) IIAC@VIN(min)u(cid:11)VVAOUT(max)(cid:16)1V(cid:12) IMOUT(max) KuVVFF2(min) (18) I forthisdesignisapproximately315mA.TheR resistorcanthenbedeterminedbyEquation19: MOUT(max) MOUT RMOUT VRSENSE IMOUT(max) (19) In this example V was selected to give a dynamic operating range of 1.25 V, which gives an R of RSENSE MOUT roughly3.91kΩ. 10.2.2.4 VoltageLoop The second major source of harmonic distortion is the ripple on the output capacitor at the second harmonic of the line frequency. This ripple is fed back through the error amplifier and appears as a 3rd harmonic ripple at the input to the multiplier. The voltage loop must be compensated not just for stability but also to attenuate the contributionofthisrippletothetotalharmonicdistortionofthesystem(seeFigure6). 18 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 Cf VOUT Rf CZ RIN – RD + VREF Figure6. VoltageAmplifierConfiguration The gain of the voltage amplifier, G , can be determined by first calculating the amount of ripple present on the VA outputcapacitor.ThepeakvalueofthesecondharmonicvoltageisgivenbyEquation20. PIN VOPK (cid:11)2SufRuCOUTuVOUT(cid:12) (20) In this example V is equal to 3.91 V. Assuming an allowable contribution of 0.75% (1.5% peak to peak) from OPK thevoltagelooptothetotalharmonicdistortionbudgetwesetthegainequaltoEquation21. (’VVAOUT)(cid:11)0.015(cid:12) GVA 2uVOPK where • ΔV istheeffectiveoutputvoltagerangeoftheerroramplifier(5VfortheUCC3817A). (21) VAOUT The network needed to realize this filter is comprised of an input resistor, R , and feedback components C, C , IN f Z and R. The value of R is already determined because of its function as one half of a resistor divider from V f IN OUT feeding back to the voltage amplifier for output voltage regulation. In this case the value was chosen to be 1 MΩ. This high value was chosen to reduce power dissipation in the resistor. In practice, the resistor value would be realized by the use of two 500-kΩ resistors in series because of the voltage rating constraints of most standard 1/4-Wresistors.ThevalueofC isdeterminedbyEquation22. f 1 Cf (2SufRuGVAuRIN) (22) In this example C equals 150 nF. Resistor R sets the dc gain of the error amplifier and thus determines the f f frequency of the pole of the error amplifier. The location of the pole can be found by setting the gain of the loop equation to one and solving for the crossover frequency. The frequency, expressed in terms of input power, can becalculatedbyEquation23. fVI2 (cid:11)(cid:11)2S(cid:12)2u’VVAOUTuVPOINUTuRINuCOUTuCf(cid:12) (23) f for this converter is 10 Hz. A derivation of this equation can be found in the Unitrode Power Supply Design VI Seminar SEM1000, Topic 1, [A 250-kHz, 500-W Power Factor Correction Circuit Employing Zero Voltage Transitions]. SolvingforR becomesEquation24. f 1 Rf (cid:11)2SufVIuCf(cid:12) (24) orRfequals100kΩ. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com Due to the low output impedance of the voltage amplifier, capacitor C was added in series with R to reduce Z F loading on the voltage divider. To ensure the voltage loop crossed over at f , C was selected to add a zero at a VI Z 10thoff .Forthisdesign,a2.2-µFcapacitorwaschosenforC .Equation25canbeusedtocalculateC . VI Z Z 1 CZ 2uSufVIuRf 10 (25) 10.2.2.5 CurrentLoop ThegainofthepowerstageiscalculatedbyEquation26. (cid:11)VOUTuRSENSE(cid:12) GID(s) (cid:11)suLBOOSTuVP(cid:12) (26) R has been chosen to give the desired differential voltage for the current sense amplifier at the desired SENSE current limit point. In this example, a current limit of 4 A and a reasonable differential voltage to the current amp of 1 V gives a R value of 0.25 Ω. VP in Equation 26 is the voltage swing of the oscillator ramp, 4 V for the SENSE UCC3817A. Setting the crossover frequency of the system to 1/10th of the switching frequency, or 10 kHz, requires a power stage gain at that frequency of 0.383. For the system to have a gain of 1 at the crossover frequency, the current amplifier needs to have a gain of 1/G at that frequency. G , the current amplifier gain is ID EA then: 1 1 GEA 2.611 GID 0.383 (27) R is the R resistor, previously calculated to be 3.9 kΩ. (see Figure 7). The gain of the current amplifier is I MOUT R/R, so multiplying R by G gives the value of R, in this case approximately 12 kΩ. Setting a zero at the f I I EA f crossoverfrequencyandapoleathalftheswitchingfrequencycompletesthecurrentloopcompensation. 1 CZ 2uSuRfufC (28) 1 CP 2uSuRfufs 2 (29) CP C Rf Z R I (cid:237) CAOUT + Figure7. CurrentLoopCompensation The UCC3817A current amplifier has the input from the multiplier applied to the inverting input. This change in architecture from previous Texas Instruments PFC controllers improves noise immunity in the current amplifier. It also adds a phase inversion into the control loop. The UCC3817A takes advantage of this phase inversion to implement leading-edge duty cycle modulation. Synchronizing a boost PFC controller to a downstream dc-to-dc controller reduces the ripple current seen by the bulk capacitor between stages, reducing capacitor size and cost and reducing EMI. This is explained in greater detail in the following section. The UCC3817A current amplifier configurationisshowninFigure8. 20 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 L BOOST VOUT Q (cid:237) RSENSE + BOOST Zf PWM MULT CA COMPARATOR (cid:237) (cid:237) + + Figure8. UCC3817ACurrentAmplifierConfiguration 10.2.2.6 Start-Up The UCC3818A version of the device is intended to have VCC connected to a 12-V supply voltage. The UCC3817A has an internal shunt regulator enabling the device to be powered from bootstrap circuitry as shown in the typical application circuit of Figure 5. The current drawn by the UCC3817A during undervoltage lockout, or start-up current, is typically 150 µA. Once VCC is above the UVLO threshold, the device is enabled and draws 4 mA typically. A resistor connected between the rectified ac line voltage and the VCC pin provides current to the shunt regulator during power up. Once the circuit is operational, the bootstrap winding of the inductor provides the VCC voltage. Sizing of the start-up resistor is determined by the start-up time requirement of the system design. ’V IC C ’t (30) R VRMSu(0.9) IC where • I isthechargecurrent C • CisthetotalcapacitanceattheVCCpin • ΔVistheUVLOthresholdandΔtistheallowedstart-uptime (31) Assuming a 1 second allowed start-up time, a 16-V UVLO threshold, and a total VCC capacitance of 100 µF, a resistor value of 51 kΩ is required at a low line input voltage of 85 V . The IC start-up current is sufficiently RMS smallastobeignoredinsizingthestart-upresistor. 10.2.2.7 CapacitorRippleReduction For a power system where the PFC boost converter is followed by a dc-to-dc converter stage, there are benefits to synchronizing the two converters. In addition to the usual advantages such as noise reduction and stability, proper synchronization can significantly reduce the ripple currents in the boost circuit's output capacitor. Figure 9 helps illustrate the impact of proper synchronization by showing a PFC boost converter together with the simplified input stage of a forward converter. The capacitor current during a single switching cycle depends on the status of the switches Q1 and Q2 and is shown in Figure 10. It can be seen that with a synchronization scheme that maintains conventional trailing-edge modulation on both converters, the capacitor current ripple is highest. The greatest ripple current cancellation is attained when the overlap of Q1 off-time and Q2 on-time is maximized. One method of achieving this is to synchronize the turnon of the boost diode (D1) with the turnon of Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com Q2. This approach implies that the boost converter's leading edge is pulse width modulated while the forward converter is modulated with traditional trailing edge PWM. The UCC3817A is designed as a leading edge modulator with easy synchronization to the downstream converter to facilitate this advantage. Table 4 compares the I for D1/Q2 synchronization as offered by UCC3817A vs the ICB(rms) for the other extreme of CB(rms) synchronizingtheturnonofQ1andQ2fora200-WpowersystemwithaV of385V. BST iD1 iQ2 LIN D1 VBST Q2 IL IIN iCB LOAD Q1 CBST Figure9. SimplifiedRepresentationofa2-StagePFCPowerSupply ON OFF Q1 OFF ON iDi ON OFF Q2 ON OFF iQ2 iCB iCB = iDi - iQ2 Figure10. TimingWaveformsforSynchronizationScheme Table 4 illustrates that the boost capacitor ripple current can be reduced by about 50% at nominal line and about 30% at high line with the synchronization scheme facilitated by the UCC3817A. Figure 11 shows the suggested technique for synchronizing the UCC3817A to the downstream converter. With this technique, maximum ripple reduction as shown in Figure 10 is achievable. The output capacitance value can be significantly reduced if its choice is dictated by ripple current or the capacitor life can be increased as a result. In cost sensitive designs whereholduptimeisnotcritical,thisisasignificantadvantage. Table4.EffectsofSynchronizationonBoostCapacitorCurrent V =85V V =120V V =240V IN IN IN D(Q2) Q1/Q2 D1/Q2 Q1/Q2 D1/Q2 Q1/Q2 D1/Q2 0.35 1.491A 0.835A 1.341A 0.663A 1.024A 0.731A 0.45 1.432A 0.93A 1.276A 0.664A 0.897A 0.614A 22 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 An alternative method of synchronization to achieve the same ripple reduction is possible. In this method, the turnon of Q1 is synchronized to the turnoff of Q2. While this method yields almost identical ripple reduction and maintains trailing edge modulation on both converters, the synchronization is much more difficult to achieve and thecircuitcanbecomesusceptibletonoiseasthesynchronizingedgeitselfisbeingmodulated. Gate Drive From Down Stream PWM C1 UCC3817A D2 CT CT D1 RT RT Copyright © 2016, Texas Instruments Incorporated Figure11. SynchronizingtheUCC3817AtoaDown-StreamConverter 10.2.3 ApplicationCurves 7.60 7.510 V 7.55 V 7.505 Reference Voltage - 7.50 eference Voltage - 7.500 –EF –F R R E V R 7.45 V 7.495 7.490 7.40 9 10 11 12 13 14 0 5 10 15 20 25 VCC – Supply Voltage - V IVREF – Reference Current - mA Figure12.ReferenceVoltagevsSupplyVoltage Figure13.ReferenceVoltagevsReferenceVoltage Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 350 1.5 IAC = 150 µA VFF = 1.4 V 300 A 1.3 (cid:29) nt - 250 IAC = 150 µA e urr Output C 200 IAVCFF = = 3 30.00 µ VA Gain - K 1.1 Multiplier 150 Multiplier 0.9 IAC = 300 µA – T 100 IAC = 500 µA U O M 0.7 I 50 IAC = 500 µA VFF = 4.7 V 0 0.5 0.0 1.0 2.0 3.0 4.0 5.0 1.0 2.0 3.0 4.0 5.0 VAOUT – Voltage Error Amplifier Output - V VAOUT – Voltage Error Amplifier Output - V Figure14.MultiplierOutputCurrentvsVoltageError Figure15.MultiplierGainvsVoltageErrorAmplifier AmplifierOutput Output 500 400 VAOUT = 5 V W (cid:29)) - T 300 OU VAOUT = 4 V M x I F 200 F V ( VAOUT = 3 V 100 VAOUT = 2 V 0 0.0 1.0 2.0 3.0 4.0 5.0 VFF – Feedforward Voltage - V Figure16.MultiplierConstantPowerPerformance 24 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 11 Power Supply Recommendations The supply voltage for the device comes from VCC pin. This pin must be bypassed with a high-frequency capacitor (greater than 1 µF) and tied to GND. The UCC3817A and UCC2817A has a wide UVLO hysteresis of approximately6.3Vthatallowsuseofalowervaluesupplycapacitoronthispinforquickerandeasierstart-up. 12 Layout 12.1 Layout Guidelines 12.1.1 BiasCurrent The bias voltage is supplied either by an external dedicated DC-DC converter or by an auxiliary winding from the PFCinductororthe2ndstageDC-DCconverter. The bias capacitor should be large enough to maintain sufficient voltage with AC line variations. Connect a 1-µF capacitorbetweenVCCandGNDasclosetotheICaspossible.Forwidelinevoltages,anadditional18-VZener clampcanalsobeused. 12.1.2 VREF Connectacapacitor>=0.1µFbetweenVREFandGNDforstability. 12.2 Layout Example D2 V0 GND HIGH TEMPERATURE - SEE EVM WARNINGS AND R18R15 RESTRICTIONS HS1 D1 Q1 D7 R14 HIGH VOLTAGE - C12 SEE EVM WARNINGS AND XL1 RESTRICTIONS C10 R16 R10 D8 L1 C11 HIGH VOLTAGE - AC2 C13 R21 R9 C2 R17GND SEE EVM WARNINGS AND RESTRICTIONS R11 C3 D4 R13 C9 U1 R22 VCC XC12 D3 C8 C1 AC1 R12 R8 C4 SYNC C15 C14 R1 R2 C7 R19 R3 C6 R7 R4 FA1 D5 D6 C5 R20 UCC3817 EVALUATION BOARD R6 R5 Figure17. UCC3817EVMEvaluationBoardLayoutAssembly Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 25 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 www.ti.com 13 Device and Documentation Support 13.1 Documentation Support 13.1.1 RelatedDocumentation Forrelateddocumentationseethefollowing: 1. DifferencesBetweenUCC3817A/18A/19AandUCC3817/18/19 (SLUA294) 2. UCC3817BiCMOSPowerFactorPreregulatorEvaluationBoard (SLUU077) 3. SynchronizingaPFCControllerfromaDownStreamControllerGateDrive (SLUA245) 4. Seminartopic,HighPowerFactorSwitchingPreregulatorDesignOptimization,L.H.Dixon,SEM-700,1990. 5. Seminartopic,HighPowerFactorPreregulatorforOff-lineSupplies,L.H.Dixon,SEM-600,1988. 13.2 Related Links The table below lists quick access links. Categories include technical documents, support and community resources,toolsandsoftware,andquickaccesstosampleorbuy. Table5.RelatedLinks TECHNICAL TOOLS& SUPPORT& PARTS PRODUCTFOLDER SAMPLE&BUY DOCUMENTS SOFTWARE COMMUNITY UCC2817A Clickhere Clickhere Clickhere Clickhere Clickhere UCC2818A Clickhere Clickhere Clickhere Clickhere Clickhere UCC3817A Clickhere Clickhere Clickhere Clickhere Clickhere UCC3818A Clickhere Clickhere Clickhere Clickhere Clickhere 13.3 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed.Forchangedetails,reviewtherevisionhistoryincludedinanyreviseddocument. 13.4 Community Resource The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TIE2E™OnlineCommunity TI'sEngineer-to-Engineer(E2E)Community.Createdtofostercollaboration amongengineers.Ate2e.ti.com,youcanaskquestions,shareknowledge,exploreideasandhelp solveproblemswithfellowengineers. DesignSupport TI'sDesignSupport QuicklyfindhelpfulE2Eforumsalongwithdesignsupporttoolsand contactinformationfortechnicalsupport. 13.5 Trademarks E2EisatrademarkofTexasInstruments. Allothertrademarksarethepropertyoftheirrespectiveowners. 13.6 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. 13.7 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 26 SubmitDocumentationFeedback Copyright©2011–2016,TexasInstrumentsIncorporated ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

UCC2817A,UCC2818A,UCC3817A,UCC3818A www.ti.com SLUS577D–NOVEMBER2011–REVISEDAUGUST2016 14 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of thisdocument.Forbrowser-basedversionsofthisdatasheet,refertotheleft-handnavigation. Copyright©2011–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 27 ProductFolderLinks:UCC2817A UCC2818A UCC3817A UCC3818A

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) UCC2817AD ACTIVE SOIC D 16 40 Green (RoHS NIPDAU Level-1-260C-UNLIM -40 to 85 UCC2817AD & no Sb/Br) UCC2817ADR ACTIVE SOIC D 16 2500 Green (RoHS NIPDAU Level-1-260C-UNLIM -40 to 85 UCC2817AD & no Sb/Br) UCC2817AN ACTIVE PDIP N 16 25 Green (RoHS NIPDAU N / A for Pkg Type -40 to 85 UCC2817AN & no Sb/Br) UCC2817APW ACTIVE TSSOP PW 16 90 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 2817A & no Sb/Br) UCC2817APWR ACTIVE TSSOP PW 16 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 2817A & no Sb/Br) UCC2818AD ACTIVE SOIC D 16 40 Green (RoHS NIPDAU Level-1-260C-UNLIM -40 to 85 UCC2818AD & no Sb/Br) UCC2818ADR ACTIVE SOIC D 16 2500 Green (RoHS NIPDAU Level-1-260C-UNLIM -40 to 85 UCC2818AD & no Sb/Br) UCC2818AN ACTIVE PDIP N 16 25 Green (RoHS NIPDAU N / A for Pkg Type -40 to 85 UCC2818AN & no Sb/Br) UCC2818APW ACTIVE TSSOP PW 16 90 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 2818A & no Sb/Br) UCC2818APWR ACTIVE TSSOP PW 16 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 2818A & no Sb/Br) UCC2818APWRG4 ACTIVE TSSOP PW 16 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 2818A & no Sb/Br) UCC3817AD ACTIVE SOIC D 16 40 Green (RoHS NIPDAU Level-1-260C-UNLIM 0 to 70 UCC3817AD & no Sb/Br) UCC3817ADR ACTIVE SOIC D 16 2500 Green (RoHS NIPDAU Level-1-260C-UNLIM 0 to 70 UCC3817AD & no Sb/Br) UCC3817AN ACTIVE PDIP N 16 25 Green (RoHS NIPDAU N / A for Pkg Type 0 to 70 UCC3817AN & no Sb/Br) UCC3818AD ACTIVE SOIC D 16 40 Green (RoHS NIPDAU Level-1-260C-UNLIM 0 to 70 UCC3818AD & no Sb/Br) UCC3818ADR ACTIVE SOIC D 16 2500 Green (RoHS NIPDAU Level-1-260C-UNLIM 0 to 70 UCC3818AD & no Sb/Br) UCC3818AN ACTIVE PDIP N 16 25 Green (RoHS NIPDAU N / A for Pkg Type 0 to 70 UCC3818AN & no Sb/Br) Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) UCC3818APW ACTIVE TSSOP PW 16 90 Green (RoHS NIPDAU Level-2-260C-1 YEAR 0 to 70 3818A & no Sb/Br) UCC3818APWR ACTIVE TSSOP PW 16 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR 0 to 70 3818A & no Sb/Br) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF UCC2818A : Addendum-Page 2

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 •Automotive: UCC2818A-Q1 NOTE: Qualified Version Definitions: •Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects Addendum-Page 3

PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) UCC2817ADR SOIC D 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 Q1 UCC2817APWR TSSOP PW 16 2000 330.0 12.4 6.9 5.6 1.6 8.0 12.0 Q1 UCC2818ADR SOIC D 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 Q1 UCC2818APWR TSSOP PW 16 2000 330.0 12.4 6.9 5.6 1.6 8.0 12.0 Q1 UCC3817ADR SOIC D 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 Q1 UCC3818ADR SOIC D 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 Q1 UCC3818APWR TSSOP PW 16 2000 330.0 12.4 6.9 5.6 1.6 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) UCC2817ADR SOIC D 16 2500 333.2 345.9 28.6 UCC2817APWR TSSOP PW 16 2000 367.0 367.0 35.0 UCC2818ADR SOIC D 16 2500 333.2 345.9 28.6 UCC2818APWR TSSOP PW 16 2000 367.0 367.0 35.0 UCC3817ADR SOIC D 16 2500 333.2 345.9 28.6 UCC3818ADR SOIC D 16 2500 333.2 345.9 28.6 UCC3818APWR TSSOP PW 16 2000 367.0 367.0 35.0 PackMaterials-Page2

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PACKAGE OUTLINE PW0016A TSSOP - 1.2 mm max height SCALE 2.500 SMALL OUTLINE PACKAGE SEATING PLANE C 6.6 TYP 6.2 A 0.1 C PIN 1 INDEX AREA 14X 0.65 16 1 2X 5.1 4.55 4.9 NOTE 3 8 9 0.30 B 4.5 16X 0.19 1.2 MAX 4.3 0.1 C A B NOTE 4 (0.15) TYP SEE DETAIL A 0.25 GAGE PLANE 0.15 0.05 0.75 0.50 0 -8 DETA 20AIL A TYPICAL 4220204/A 02/2017 NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. 4. This dimension does not include interlead flash. Interlead flash shall not exceed 0.25 mm per side. 5. Reference JEDEC registration MO-153. www.ti.com

EXAMPLE BOARD LAYOUT PW0016A TSSOP - 1.2 mm max height SMALL OUTLINE PACKAGE 16X (1.5) SYMM (R0.05) TYP 1 16X (0.45) 16 SYMM 14X (0.65) 8 9 (5.8) LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE: 10X SOLDER MASK METAL UNDER SOLDER MASK OPENING METAL SOLDER MASK OPENING EXPOSED METAL EXPOSED METAL 0.05 MAX 0.05 MIN ALL AROUND ALL AROUND NON-SOLDER MASK SOLDER MASK DEFINED DEFINED (PREFERRED) SOLDE15.000R MASK DETAILS 4220204/A 02/2017 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com

EXAMPLE STENCIL DESIGN PW0016A TSSOP - 1.2 mm max height SMALL OUTLINE PACKAGE 16X (1.5) SYMM (R0.05) TYP 1 16X (0.45) 16 SYMM 14X (0.65) 8 9 (5.8) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE: 10X 4220204/A 02/2017 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com

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IMPORTANTNOTICEANDDISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS” AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable warranties or warranty disclaimers for TI products. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2020, Texas Instruments Incorporated