Buck Current/Voltage Fed Push-Pull PWM Controllers (Rev. D)

1 RDQS20 DELAY23 GND11 VCCREF15RT17CT18 SYNC19 CSA 9 CSA+8SS4 CSAO7 CEA 13 VEA 16 VEA+142224321 RAMPCEA+12 CEAOVEAO10 PULLPGNDPUSHSRCBUCKV+DELAYDELAYTQQREF&UV LOSSINHBTUVOSC500 kHzMAX6521 current SenseAmplifierILIM Comparator+3 VCurrent ErrorAmplifierPWM VFlyingDriverPush/PullDriversOSCUVLOV oltage ErrorAmplifier+UC2827-1,UC2827-2UC3827-1 , APRIL1999 REVISEDAPRIL2011 BUCKCURRENT/VOLTAGEFEDPUSH-PULLPWMCONTRO LLERSC heckforSamples:UC2827-1,UC2827-2, UC3827-1,UC3827-21 FEATURESDESCRIPTION IdealforMultipleOutputand/orHighTheUC382 7familyofcontrollerdevicesprovidesanVolt ageOutputVoltageConvertersintegratedcont rolsolutionforcascadedbuckand HighVoltage,HighCurrentFloatingcurrentfe dorvoltagefedpush- UC3827-1 CurrentFedControllerhasvoltagefedmodes,t hepush-pullswitchesaredrivenPush-PullDri verswithOverlappingat50% UC3827-2 VoltageFedControllerhasfedmode, ,thetwoswitchesaredrivenwitha specified AverageCurrentMode,PeakCurrentgaptimebet weentheswitchestopreventshortingModeorVo ltageModewithInputthetransformeracrossth eenergystoragecapacitorVoltageFeedforwar dControlforBuckandtoprohibitexcessivecur rentsflowingthroughthePowerStagedevices.

2 WideBandwidth,LowOffset,Theconverter's ,standardwarranty,andusein 1999 2011, ,UC2827-2UC3827-1,UC3827-2 SLUS365D APRIL1999 (CONTINUED) timingandin , parallelwiththevoltageregulationlooptoas sistonlyin ,userprogrammableoverlaptime(UC3827-1),u serprogrammablegaptime(UC3827-2),a highbandwidthdifferentialcurrentsenseamp lifier, (1)PACKAGESTA= TJPUSH-PULLTOPOLOGYSOIC-24 PDIP-24 PLCC-28 CurrentFedUC2827DW-1UC2827N-1--40 C to85 CVoltageFedUC2827DW-2UC2827N-2-CurrentFe dUC3827DW-1UC3827N-1UC3827Q-10 C to70 CVoltageFedUC3827DW-2UC3827N-2-(1)TheDWa ndQ TRsuffixtothedevicetype( ,UC2827 DWTR-1).THERMALINFORMATIONUC2827-1,UC282 7-1,UC2827-2,UC2827-2,UC3827-1,UC3827-1, THERMALMETRICUNITSUC3827-2UC3827-2NJ24 PINS24 PINS JAJunction-to-ambientthermalresistance(1 )6070to80 C/W JCtopJunction-to-case(top)thermalresista nce(2)3028(1)Thejunction-to-ambienttherm alresistanceundernaturalconvectionis obtainedin a simulationona JEDEC-standard,high-Kboard,asspecifiedin JESD51-7,in anenvironmentdescribedin JESD51-2a.

3 (2)Thejunction-to-case(top)thermalresist anceis obtainedbysimulatinga ,buta closedescriptioncanbefoundin ,UC2827-1,UC2827-2,UC2827-2,UC3827-1,UC3 827-1,THERMALMETRICUNITSUC3827-2UC3827-2 DW(1)QLCC28 PINS28 PINS JAJunction-to-ambientthermalresistance(2 )71to8340to65 C/W JCtopJunction-to-case(top)thermalresista nce(3)2430(1)Formoreinformationabouttrad itionalandnewthermalmetrics,seetheICPack ageThermalMetricsapplicationreport,SPRA9 53.(2)Thejunction-to-ambientthermalresis tanceundernaturalconvectionis obtainedin a simulationona JEDEC-standard,high-Kboard,asspecifiedin JESD51-7,in anenvironmentdescribedin JESD51-2a.(3)Thejunction-to-case(top)the rmalresistanceis obtainedbysimulatinga ,buta closedescriptioncanbefoundin 1999 2011,TexasInstrumentsIncorporatedUC2827- 1,UC2827-2UC3827-1, APRIL1999 REVISEDAPRIL2011 ABSOLUTEMAXIMUMRATINGS(1)UC2827-1UC2827- 2 UNITSUC3827-1UC3827-2 Supplyvoltage,VCC20 CEAO,CEA+,CEA-,CSAO,CSA+,CSA-,CT,DELAY,P USH, pull , ,RT,SS,SYNC,VEA+,VEAO,VInputvoltagerange V+andBUCK90 SRC90-VCCI/Ocontinuous 250mABUCK driverI/Opeak 1AI/Ocontinuous 200mAPUSH/ pull driverI/Opeak 65to150 Junctiontemperature 55to150 CLeadtemperature(soldering,10sec)300(1) , ,VVCC= 15V,VV+= ,CCT= 340pF,RRT= 10k , RDELAY= , VSRC= VGND= VBUCK=VPUSH= VPULL outputsnoload,TJ= TAPARAMETERTESTCONDITIONSMINTYPMAXUNITSU PPLYVCCUVLO, 8 V1000 AIVCCS upplycurrentrun3245mAIV+ AVIO10mVAVOL8095dBGBW(1)Gainbandwidth14 MHzVOLLow-leveloutputvoltageIVEAO= 0 A (Noload)

4 0 A (Noload) 1 5 AVIO5mVAVOL80110dBGBW(1)Gainbandwidth152 9 MHzVOLLow-leveloutputvoltageICEAO= 0 A (Noload) 0 A (Noload) (1) (1) 1999 2011,TexasInstrumentsIncorporated3UC2827 -1,UC2827-2UC3827-1,UC3827-2 SLUS365D APRIL1999 (continued)Unlessotherwisespsecified,VVC C= 15V,VV+= ,CCT= 340pF,RRT= 10k , RDELAY= , VSRC= VGND= VBUCK=VPUSH= VPULL outputsnoload,TJ= TAPARAMETERTESTCONDITIONSMINTYPMAXUNITCU RRENTERRORAMPLIFIERIB 1 5 AVIO10mVAVOL80110dBGBW(2)GainbandwidthAt 100kHz, 0 A (NoLoad) 0 A (NoLoad) (2) (dsch) nFLoad(3)40100nstFALLF alltIme1 nF,Load3080nsIBUCK= 15mA, V+ buck (4) 150mA,V+ buck (4) 15mA(5) = 150mA(5) nFload50100nstFALLF alltIme1 nFload35100nsOverlaptimeUCx827-11 nFloads(6)100250400nsNonoverlappingtime( 7)UCx827-2100250500nsIPUSH/ pull = 10mA,VCC PUSH23V(8)VOHHigh-leveloutputvoltageIPUS H/ pull = 100mA,VCC (8)IPUSH/ pull = 10mA(8) 100mA(8) 0V 35 50 <VVCC<20V520mVLoadregulation0 mA<IIO<10mA820mVSOFTSTARTVOLLow-levelout putvoltagesaturationVVCC= 7 V250500mVISSSoft-startcurrent 5 12 25 A(2) (3)MeasuretherisetimefromwhenBUCK crosses1 V untilit crosses9 V.

5 (4)ToforceBUCK high,forceVCSAO= ,VCEAO= ,a 25-k pulldownresistorfromRAMP toground,andVCT= (5)ToforceBUCKlow,forceVCSAO= ,VCEAO= ,a 10-k pulldownresistorfromRAMP toground,andVCT= (6)Theoverlaptimeis measuredfromthepointatwhichtherisingedge ofPUSH/ pull crosses5 V untilthefallingedgeofPULL/ push crosses5V.(7)Thenon-overlaptimeis measuredfromthepointatwhichthefallingedg eofPUSH/ pull crosses5 V untiltherisingedgeofPULL/ push crosses5 V.(8)TotogglePUSHorPULL intoa desiredstate, 1999 2011,TexasInstrumentsIncorporatedfOSC+ CCT(Hz)tDELAY+RDELAY200W 10*9(s)1234 56789101112242322212019181716151413V+BUC KSRCSSRAMPCEAOCSAOCSA+CSA VEAOGNDCEA+PUSHVCCPULLPGNDDELAYSYNCCTRTV EA REFVEA+CEA N, J OR DW PACKAGES(TOP VIEW)3 2 113 14567891011 PGNDNCNCDELAYSYNCCTRTSSRAMPCEAOCSAOCSA+C SA VEAO415161718 CEA+CEA VEA+REFNCVEA SRCBUCKNCV+Q PACKAGE(TOP VIEW)28 27 262524232221201912 GNDPUSHVCCPULLNC No internal connection(1)(2)UC2827-1,UC2827-2UC3827- 1, APRIL1999 REVISEDAPRIL2011 PLCC-28(QPACKAGE)CONNECTIONDIAGRAMS(TOPV IEW)DIL-24(NorJ,DWPACKAGES)(TOPVIEW)Term inalFunctionsTERMINALI/ODESCRIPTIONN a floatingdriver, (low).

6 CEA+ + ,thebuckgatedriveCSAO78 Opulseis resistorRT, practicalmaximumvalueforthedischargecurr entis givenbyequation(1)A ,RDELAY,is 18k . Thedelayoroverlaptimeis givenbyequation(2) ,voltagesense,currentsense, imperativetopreventlarge, 50% (low).Copyright 1999 2011,TexasInstrumentsIncorporated5 IRT+ VRRT(3)UC2827-1,UC2827-2UC3827-1,UC3827- 2 SLUS365D APRIL1999 (continued)TERMINALI/ODESCRIPTIONN 50% (low).TheRAMP voltage ,aftera 700mVinternallevelshift,is resistortoVINanda capacitortoGNDprovideaninputvoltagefeedf orwardsignalforthebuckcontrollerin , ,theRAMP pinhasa ,orbyconnectingbotha resistorfromVCCtoRAMP anda + offREF1516 Owhenthechipis in equation(3). Thechargecurrentshouldbelessthan500 ART1719 ItokeepCT'sdischargepeakcurrentlessthan2 0mA,whichis CT' ,whichsetsthemaximumdutycycle,is setinternallyandis VVCC.

7 Also,duringturn-offtransientsofthebucksw itch,thevoltageatSRCcangoto ,SSis bidirectionalpinfortheoscillator., whentheoscillatorcapacitor,CT, is 0 therecommendedsynchronizationcircuitis notused,a 1 k is recommendedtobypassVCC2327 IthispintobothGNDandPGND groundconnectionswithgoodqualityhighfreq uencycapacitorsVEA+ +11 IdiodemustbeconnectedfromVCCtoV+ Thereservoircapacitormustbeconnectedbetw eenV+ 1999 2011,TexasInstrumentsIncorporated+ VOSCILLATORVREF10 VRTCTVDG 99086 IRT+ VRRTUC2827-1,UC2827-2UC3827-1, APRIL1999 showninEquation1. A resistor(RT) connectedtopinRTsetsthelinearchargecurre nt:(1)Thetimingcapacitor(CCT) is linearlychargedwiththechargecurrentforci ngtheOSCpintochargetoa ,theRSflip-flopissetdrivingCLKSYN highandRDEAD lowwhichdischargesCCT. CTcontinuestodischargeuntilit reachesa thresholdandresetstheRSflip-flopwhichrep eatsthechargingsequenceasshownin Figure2 AsshowninFigure3, , thesynchronizationthresholdis , , 1999 2011,TexasInstrumentsIncorporated7 OSCCLKSYNOUTTHRESHOLDC hargingVAO V0 VVDG 99087 CLKSYN BUSOSC1 OSC2 OSC3 OSC10 SYNCSYNCSYNCSYNC100 pF100 pF100 pF100 pF10 kWVDG 99085UC2827-1,UC2827-2UC3827-1,UC3827-2 SLUS365D APRIL1999 ( 0 - 2 V)to( 2 V)SLUS365A8/2005 ImprovedCMRRofCEAfrom( 0 - 5 V)to( 5 V)SLUS365D4/2011 UpdatedtheThermalInformationSection8 Copyright 1999 2011,TexasInstrumentsIncorporatedPACKAGE OPTION 1 PACKAGING INFORMATIONO rderable DeviceStatus(1)Package TypePackageDrawingPinsPackageQtyEco Plan(2)Lead/Ball Finish(6)MSL Peak Temp(3)Op Temp ( C)Device Marking(4/5)SamplesUC2827DW-1 ACTIVESOICDW2425 Green (RoHS& no Sb/Br)

8 CU NIPDAUL evel-3-260C-168 HR-40 to 85UC2827DW-1UC2827DW-2 ACTIVESOICDW2425 Green (RoHS& no Sb/Br)CU NIPDAUL evel-3-260C-168 HR-40 to 85UC2827DW-2UC2827 DWTR-1 ACTIVESOICDW242000 Green (RoHS& no Sb/Br)CU NIPDAUL evel-3-260C-168 HR-40 to 85UC2827DW-1UC2827 DWTR-1G4 ACTIVESOICDW242000 Green (RoHS& no Sb/Br)CU NIPDAUL evel-3-260C-168 HR-40 to 85UC2827DW-1UC3827DW-1 ACTIVESOICDW2425 Green (RoHS& no Sb/Br)CU NIPDAUL evel-3-260C-168 HR0 to 70UC3827DW-1UC3827DW-2 ACTIVESOICDW2425 Green (RoHS& no Sb/Br)CU NIPDAUL evel-3-260C-168 HR0 to 70UC3827DW-2 (1) The marketing status values are defined as follows:ACTIVE: Product device recommended for new : TI has announced that the device will be discontinued, and a lifetime-buy period is in : Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new : Device has been announced but is not in production.

9 Samples may or may not be : 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 substancedo not exceed 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 mayreference 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 : 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 basedflame retardants must also meet the <=1000ppm threshold requirement.

10 (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 continuationof the previous line and the two combined represent the entire Device Marking for that device. PACKAGE OPTION 2(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 finishvalue 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.