TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 POWER GOOD FAST-TRANSIENT RESPONSE 7.5-A LOW-DROPOUT VOLTAGE REGULATORS FEATURES TO–220 (KC) PACKAGE • 7.5-ALow-DropoutVoltageRegulator (TOP VIEW) • Availablein1.5-V,1.8-V,2.5-V,and3.3-V EN 1 Fixed-OutputandAdjustableVersions IN 2 • OpenDrainPower-Good(PG)StatusOutput GND 3 OUTPUT 4 (FixedOptionsOnly) FB/PG 5 • DropoutVoltageTypically400mVat7.5A (TPS75933) TO–263 (KTT) PACKAGE (TOP VIEW) • Low125µATypicalQuiescentCurrent • FastTransientResponse EN 1 • 3%ToleranceOverSpecifiedConditionsfor IN 2 GND 3 Fixed-OutputVersions OUTPUT 4 • Availablein5-PinTO-220andTO-263 FB/PG 5 Surface-MountPackages • ThermalShutdownProtection DESCRIPTION The TPS759xx family of 7.5-A low dropout (LDO) regulators contains four fixed voltage option regulators with integrated power-good (PG) and an adjustable voltage option regulator. These devices are capable of supplying 7.5Aofoutputcurrentwithadropoutof400mV(TPS75933).Therefore,thedevicesarecapableofperforming a 3.3-V to 2.5-V conversion. Quiescent current is 125 µA at full load and drops below 10 µA when the devices are disabled.TheTPS759xxisdesignedtohavefasttransientresponseforlargeloadcurrentchanges. TPS75933 DROPOUT VOLTAGE TPS75915 vs LOAD TRANSIENT RESPONSE JUNCTION TEMPERATURE V 600 m 200 IO = 7.5 A age – 100 VCOo == 110.50 Vm F ddti(cid:1)1(cid:1)sA 500 olt V mV ut 0 e – 400 Outp ag n –100 olt e i V g ut 300 an –200 o h p C A – Dro 200 – VO 10 ent – DO D 5 urr V C 100 put 0 ut O – 0–40 –25 –10 –5 20 35 50 65 80 95 110 125 0 20 40 60 80 100 120 140 160 180 200 I O TJ – Junction Temperature – °C t – Time – m s Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofTexas Instrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet. PowerPADisatrademarkofTexasInstruments. PRODUCTIONDATAinformationiscurrentasofpublicationdate. Copyright©2000–2004,TexasInstrumentsIncorporated Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarilyincludetestingofallparameters.

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 Because the PMOS device behaves as a low-value resistor, the dropout voltage is very low (typically 400 mV at an output current of 7.5 A for the TPS75933) and is directly proportional to the output current. Additionally, since the PMOS pass element is a voltage-driven device, the quiescent current is very low and independent of output loading (typically 125 µA over the full range of output current, 1 mA to 7.5 A). These two key specifications yield asignificantimprovementinoperatinglifeforbattery-poweredsystems. Thedevice is enabled when ENis connected to a low-level voltage. This LDO family also features a sleep mode; applying a TTL high signal to EN (enable) shuts down the regulator, reducing the quiescent current to less than 1 µA at T = 25(cid:176)C. The power-good terminal (PG) is an active low, open drain output, which can be used to J implementapower-onresetoralow-batteryindicator. The TPS759xx is offered in 1.5-V, 1.8-V, 2.5-V, and 3.3-V fixed-voltage versions and in an adjustable version (programmable over the range of 1.22 V to 5 V). Output voltage tolerance is specified as a maximum of 3% over line, load, and temperature ranges. The TPS759xx family is available in a 5-pin TO-220 (KC) and TO-263 (KTT) packages. AVAILABLEOPTIONS OUTPUTVOLTAGE TO-220 TO-263 T J (TYP) (KC) (KTT)(1) 3.3V TPS75933KC TPS75933KTT 2.5V TPS75925KC TPS75925KTT -40(cid:176)C to125(cid:176)C 1.8V TPS75918KC TPS75918KTT 1.5V TPS75915KC TPS75915KTT Adjustable1.22Vto5V TPS75901KC TPS75901KTT (1) TheTPS75901isprogrammableusinganexternalresistordivider(seeapplicationinformation).AddTforKTTdevicesin50-piecereel. AddRforKTTdevicesin500-piecereel. 2 5 VI IN PG PG 4 OUT VO 1 m F 1 EN Co(1) + 47 m F GND 3 (1) See application information section for capacitor selection details. Figure1.TypicalApplicationConfiguration(ForFixedOutputOptions) TerminalFunctions(TPS759xx) TERMINAL I/O DESCRIPTION NAME NO. EN 1 I Enableinput FB/PG 5 I/O Feedbackinputvoltageforadjustabledevice/PGoutputforfixedoptions GND 3 Regulatorground IN 2 I Inputvoltage OUTPUT 4 O Regulatedoutputvoltage 2

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 FUNCTIONALBLOCKDIAGRAM-ADJUSTABLEVERSION VIN VOUT UVLO Current Sense SHUTDOWN ILIM R1 GND _ + FB EN UVLO R2 Thermal Shutdown External to the Device Vref = 1.22 V Bandgap VIN Reference FUNCTIONALBLOCKDIAGRAM-FIXEDVERSION VIN VOUT UVLO Current Sense SHUTDOWN ILIM R1 _ + GND UVLO EN R2 Thermal Shutdown Vref = 1.22 V VIN RBeafnedregnacpe PG Falling Edge Delay 3

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TPS759xx PG TIMING DIAGRAM VIN1 VUVLO VUVLO t VOUT VIT+(see Note A) Threshold Voltage VIT– (see Note A) t PG Output t NOTE A: VIT –Trip voltage is typically 9% lower than the output voltage (91%VO) VIT– to VIT+ is the hysteresis voltage. DETAILED DESCRIPTION The TPS759xx family includes four fixed-output voltage regulators (1.5 V, 1.8 V, 2.5 V, and 3.3 V), and an adjustableregulator,theTPS75901(adjustablefrom1.22Vto5V).Thebandgapvoltageistypically1.22V. PIN FUNCTIONS Enable(EN) The EN terminal is an input which enables or shuts down the device. If EN is a logic high, the device will be in shutdownmode.WhenENgoestologiclow,thenthedevicewillbeenabled. Power-Good(PG) The PG terminal for the fixed voltage option devices is an open drain, active low output that indicates the status of V (output of the LDO). When V reaches approximately 91% of the regulated voltage, PG will go to a low O O impedance state. It will go to a high-impedance state when V falls below 91% (i.e., over load condition) of the O regulatedvoltage.TheopendrainoutputofthePGterminalrequiresapullupresistor. Feedback(FB) FB is an input terminal used for the adjustable-output option and must be connected to the output terminal either directly, in order to generate the minimum output voltage of 1.22 V, or through an external feedback resistor divider for other output voltages. The FB connection should be as short as possible. It is essential to route it in such a way to minimize/avoid noise pickup. Adding RC networks between FB terminal and V to filter noise is O notrecommendedbecauseitmaycausetheregulatortooscillate. 4

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 InputVoltage(IN) TheV terminalisaninputtotheregulator. IN OutputVoltage(OUTPUT) TheV terminalisanoutputtotheregulator. OUTPUT ABSOLUTE MAXIMUM RATINGS overoperatingjunctiontemperaturerange(unlessotherwisenoted)(1) TPS759XX Inputvoltagerange(2) V -0.3Vto6V I VoltagerangeatEN -0.3Vto6V MaximumPGvoltage(TPS759xx) 6V Peakoutputcurrent Internallylimited Continuoustotalpowerdissipation SeeDissipationRatingTable Outputvoltage V (OUTPUT,FB) 5.5V O Operatingjunctiontemperaturerange T -40(cid:176)C to150(cid:176)C J Storagetemperaturerange T -65(cid:176)C to150(cid:176)C stg ESDrating HBM 2kV CDM 500V (1) Stressesbeyondthoselistedunderabsolutemaximumratingsmaycausepermanentdamagetothedevice.Thesearestressratings only,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderrecommendedoperating conditionsisnotimplied.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. (2) Allvoltagevaluesarewithrespecttonetworkterminalground. DISSIPATION RATING TABLE PACKAGE RQJC ((cid:176)C/W) RQJA ((cid:176)C/W) (1) TO-220 2 58.7(2) TO-263 2 38.7(3) (1) Forbothpackages,theRQJA valueswerecomputedusingJEDEC highKboard(2S2P)with1ounceinternalcopperplaneandground plane.Therewasnoairflowacrossthepackages. (2) RQJA wascomputedassumingavertical,freestandingTO-220 packagewithpinssolderedtotheboard.Thereisnoheatsink attachedtothepackage. (3) RQJA wascomputedassumingahorizontallymountedTO-263 packagewithpinssolderedtotheboard.Thereisnocopperpad underneaththepackage. RECOMMENDED OPERATING CONDITIONS MIN MAX UNIT VI(1) Inputvoltage 2.8 5.5 V V Outputvoltagerange 1.22 5 V O I Outputcurrent 0 7.5 A O T Operatingvirtualjunctiontemperature -40 125 (cid:176)C J (1) Tocalculatetheminimuminputvoltageforyourmaximumoutputcurrent,usethefollowingequation:V =V +V . I(min) O(max) DO(maxload) 5

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 ELECTRICAL CHARACTERISTICS overrecommendedoperatingjunctiontemperaturerange(T =-40(cid:176)C to125(cid:176)C), V =V +1V,I =1mA,EN=0V, J I O(typ) O C =100µF(unlessotherwisenoted) O PARAMETER TESTCONDITIONS MIN TYP MAX UNIT 1.22V£ V £ 5.5V,T =25(cid:176)C V O J O 1.22V£ V £ 5.5V 0.97V 1.03V Adjustablevoltage O O O V 1.22V£ V £ 5.5V,T =0to 125(cid:176)C (2) O J 0.98VO 1.02VO T =25(cid:176)C, 2.8V<V <5.5V 1.5 J I 1.5VOutput 2.8V£ V £ 5.5V 1.455 1.545 I Outputvoltage(1) T =25(cid:176)C, 2.8V<V <5.5V 1.8 V J I 1.8VOutput 2.8V£ V £ 5.5V 1.746 1.854 I T =25(cid:176)C, 3.5V<V <5.5V 2.5 J I 2.5VOutput V 3.5V£ V £ 5.5V 2.425 2.575 I T =25(cid:176)C, 4.3V<V <5.5V 3.3 J I 3.3VOutput V 4.3V£ V £ 5.5V 3.201 3.399 I T =25(cid:176)C 125 Quiescentcurrent(GNDcurrent)(3),(4) J µA 200 V +1V£ V£ 5.5V,T =25(cid:176)C 0.04 Outputvoltagelineregulation(DV /V )(4) O I J %/V O O V +1V£ V <5.5V 0.1 O I Loadregulation(3) 0.35 %/V BW=300Hzto50kHz,T =25(cid:176)C, Outputnoisevoltage TPS75915 J 35 µVrms V =2.8V I Outputcurrentlimit V =0V 8 10 14 A O Thermalshutdownjunctiontemperature 150 (cid:176)C EN=V ,T =25(cid:176)C 0.1 µA I J Standbycurrent EN=V 10 µA I FBinputcurrent TPS75901 FB=1.5V -1 1 µA Powersupplyripplerejec- f=100Hz,T =25(cid:176)C, V =2.8V, TPS75915 J I 58 dB tion I =7.5A O MinimuminputvoltageforvalidPG I =300µA,V £ 0.8V 0 V O(PG) (PG) PGtripthresholdvoltage Fixedoptionsonly V decreasing 89 93 %V O O PGhysteresisvoltage Fixedoptionsonly MeasuredatV 0.5 %V O O PGoutputlowvoltage Fixedoptionsonly V =2.8V,I =1mA 0.15 0.4 V I O(PG) PGleakagecurrent Fixedoptionsonly V =5V 1 µA (PG) EN=V -1 1 µA I Inputcurrent(EN) EN=0V -1 0 1 µA HighlevelENinputvoltage 2 V LowlevelENinputvoltage 0.7 V (1) I =0mAto7.5A O (2) Theadjustableoptionoperateswitha2%toleranceoverT =0to125(cid:176)C. J (3) I =0mAto7.5A O (4) IfV £ 1.8VthenV =2.8V,V =5.5V: O Imin Imax Line regulator (mV)(cid:3)(%V)(cid:1)VO(cid:4)VIm1ax00(cid:2)2.8V(cid:5)(cid:1)1000 IfV ‡ 2.5VthenV =V +1V,V =5.5V: O Imin O Imax Line regulator (mV)(cid:4)(%V)(cid:1)VO(cid:5)VImax(cid:3)10(cid:5)0VO(cid:2)1V(cid:6)(cid:6)(cid:1)1000 6

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 ELECTRICAL CHARACTERISTICS (continued) overrecommendedoperatingjunctiontemperaturerange(T =-40(cid:176)C to125(cid:176)C), V =V +1V,I =1mA,EN=0V, J I O(typ) O C =100µF(unlessotherwisenoted) O PARAMETER TESTCONDITIONS MIN TYP MAX UNIT Dropoutvoltage(3.3Vout- IO=7.5A,VI=3.2V,TJ=25(cid:176)C 400 mV V put)(5) I =7.5A,V =3.2V 750 mV O O I Dischargetransistorcurrent VO=1.5V,T =25(cid:176)C 10 25 mA J UVLO T =25(cid:176)C, V rising 2.2 2.75 V J I V I UVLOhysteresis T =25(cid:176)C, V falling 100 mV J I (5) INvoltageequalsV (Typ)-100mV;TPS75915,TPS75918,andTPS75925dropoutvoltagelimitedbyinputvoltagerangelimitations O (i.e.,TPS75933inputvoltageissetto3.2Vforthepurposeofthistest). 7

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS Table of Graphs FIGURE vsOutputcurrent 2,3 V Outputvoltage O vsJunctiontemperature 4,5 Groundcurrent vsJunctiontemperature 6 Powersupplyripplerejection vsFrequency 7 Outputspectralnoisedensity vsFrequency 8 z Outputimpedance vsFrequency 9 o vsInputvoltage 10 V Dropoutvoltage DO vsJunctiontemperature 11 V Minimumrequiredinputvoltage vsOutputvoltage 12 I Linetransientresponse 13,15 Loadtransientresponse 14,16 V Outputvoltageandenablevoltage vsTime(start-up) 17 O Equivalentseriesresistance(ESR) vsOutputcurrent 19,20 TPS75933 TPS75915 OUTPUTVOLTAGE OUTPUTVOLTAGE vs vs OUTPUTCURRENT OUTPUTCURRENT 3.345 1.545 VI = 4.3 V VI = 2.8 V TJ = 25°C TJ = 25°C 3.330 1.530 V V − 3.315 − 1.515 e e g g a a olt olt V 3.3 V 1.5 ut ut p p ut ut O O − 3.285 − 1.485 O O V V 3.270 1.470 3.255 1.455 0 1.5 3 4.5 6 7.5 0 1.5 3 4.5 6 7.5 IO − Output Current − A IO − Output Current − A Figure2. Figure3. 8

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS (continued) TPS75933 TPS75915 OUTPUTVOLTAGE OUTPUTVOLTAGE vs vs JUNCTIONTEMPERATURE JUNCTIONTEMPERATURE 3.345 1.545 VI = 4.3 V VI = 2.8 V 3.33 1.530 V V − 3.315 − 1.515 e e g g a a olt olt V 3.3 V 1.5 ut ut p p ut ut O O − 3.285 − 1.485 O O V V 3.270 1.470 3.255 1.455 −40 −25 10 5 20 35 50 65 80 95 110125 −40−25 −10 5 20 35 50 65 80 95 110 125 TJ − Junction Temperature − °C TJ − Junction Temperature − °C Figure4. Figure5. TPS759xx TPS75933 GROUNDCURRENT POWERSUPPLYRIPPLEREJECTION vs vs JUNCTIONTEMPERATURE FREQUENCY 118 90 VI = 5 V B VI = 4.3 V 116 IO = 7.5 A n − d 80 CTJo == 2150°0C m F o 70 114 cti IO = 1 mA e A ej 60 R mnt − 112 pple 50 urre 110 y Ri 40 C pl und 108 Sup 30 ro er IO = 7.5 A G w 20 106 Po R − 10 104 R PS 0 102 −40 −25 −10 5 20 35 50 65 80 95 110 125 10 100 1k 10k 100k 1M 10M TJ − Junction Temperature − °C f − Frequency − Hz Figure6. Figure7. 9

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS (continued) TPS75933 TPS75933 OUTPUTSPECTRALNOISEDENSITY OUTPUTIMPEDANCE vs vs FREQUENCY FREQUENCY 2.5 100 VI = 4.3 V VI = 4.3 V V/Hz 2 VCTJOo === 21350.3°0C Vm F 10 CTJo == 2150°0C m F IO = 1 mA mDensity − 1.5 IO = 7.5 A Wpedance − 0.11 e m ois IO = 1 mA ut I 0.01 al N 1 utp r O ect − 0.001 IO = 7.5 A p o S z ut 0.5 p ut 0.0001 O 0 0.00001 1100 100 1k 10k 100k 10 100 1k 10k 100k 1M 10M f − Frequency − Hz f − Frequency − Hz Figure8. Figure9. TPS75901 TPS75933 DROPOUTVOLTAGE DROPOUTVOLTAGE vs vs INPUTVOLTAGE JUNCTIONTEMPERATURE 700 600 IO = 7.5 A IO = 7.5 A 600 500 V V − m 500 TJ = 125°C − m e e 400 g g a a olt 400 olt ut V TJ = 25°C ut V 300 o o p 300 p o o − Dr TJ = −40°C − Dr 200 O 200 O D D V V 100 100 0 0 2.5 3 3.5 4 4.5 5 −40 −25 −10 −5 20 35 50 65 80 95 110 125 VI − Input Voltage − V TJ − Junction Temperature − °C Figure10. Figure11. 10

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS (continued) MINIMUMREQUIREDINPUTVOLTAGE vs TPS75915 OUTPUTVOLTAGE LINETRANSIENTRESPONSE 4 IO = 7.5 A mV VO = 1.5 V e − V TJ = 125°C age − 50 ICOo = = 71.050 A m F Voltag TJ = 25°C ut Volt 0 nput TJ = −40°C Outp −50 ed I 3 e in −100 uir ng eq 2.8 ha V R C − m − e u O ag Minim DV 3.7 ut Volt − 2.8 p VI − In 2 VI 0 50 100 150 200 250 300 350 400 450 500 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 t − Time − m s VO − Output Voltage − V Figure12. Figure13. TPS75915 TPS75933 LOADTRANSIENTRESPONSE LINETRANSIENTRESPONSE 200 Output Voltage − mV −1100000 VCOo == 110.50 Vm F ddti(cid:1)1(cid:1)sA Output Voltage − mV −55000 VICOOo = == 7 13.50.3 0A Vm F − Change in VO−200 150 Current − A − Change in VO−100 5.3 oltage − V D put D ut V 0 ut 4.3 np − O − I 0 20 40 60 80 100 120 140 160 180 200 I O 0 50 100 150 200 250 300 350 400 450 500 VI t − Time − m s t − Time − m s Figure14. Figure15. 11

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS (continued) TPS75933 OUTPUTVOLTAGEANDENABLEVOLTAGE TPS75933 vs LOADTRANSIENTRESPONSE TIME(START-UP) 200 put Voltage − mV 1000 VCOo == 130.30 Vm F di(cid:1)1A utput Voltage − V 3.3 VITOJI === 1420.53 °m CVA ut −100 dt (cid:1)s O O − n O e i −200 V 0 g n A − ChaO 170.5urrent − ge − V 4.3 V 5 C a 0 D put Volt 0 Out ble − na I O E 0 20 40 60 80 100 120 140 160 180 200 0 0.2 0.4 0.6 0.8 1 t − Time − m s t − Time (Start-Up) − ms Figure16. Figure17. 12

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 TYPICAL CHARACTERISTICS (continued) To Load VI IN OUT + Co RL EN GND ESR Figure18.TestCircuitforTypicalRegionsofStability (SeeFigure19andFigure20)(FixedOutputOptions) TYPICALREGIONOFSTABILITY TYPICALREGIONOFSTABILITY EQUIVALENTSERIESRESISTANCE(A) EQUIVALENTSERIESRESISTANCE(A) vs vs OUTPUTCURRENT OUTPUTCURRENT 10 10 Co = 680 m F Co = 47 m F Wce − TJ = 25°C We − TJ = 25°C n c a n Resist 1 esista 1 es Region of Stability s R Region of Stability Seri erie ent nt S val ale 0.2 qui 0.1 uiv E q SR − R − E Region of Instability E S E 0.015 Region of Instability 0.01 0.01 0 1.5 3 4.5 6 7.5 0 1.5 3 4.5 6 7.5 IO − Output Current − A IO − Output Current − A Figure19. Figure20. A. Equivalent series resistance (ESR) refers to the total series resistance, including the ESR of the capacitor, ay seriesresistanceaddedexternally,andPWBtraceresistancetoC . O 13

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION The amount of heat that an LDO linear regulator generates is directly proportional to the amount of power it dissipates during operation. All integrated circuits have a maximum allowable junction temperature (T max) J above which normal operation is not assured. A system designer must design the operating environment so that the operating junction temperature (T ) does not exceed the maximum junction temperature (T max). The two J J main environmental variables that a designer can use to improve thermal performance are air flow and external heatsinks. The purpose of this information is to aid the designer in determining the proper operating environment foralinearregulatorthatisoperatingataspecificpowerlevel. Ingeneral,themaximumexpectedpower(P )consumedbyalinearregulatoriscomputedas: D(max) (cid:5) (cid:6) PDmax(cid:4) VI(avg)(cid:3)VO(avg) (cid:1)IO(avg) (cid:2) VI(avg)xI(Q) (1) Where: • V istheaverageinputvoltage. I(avg) • V istheaverageoutputvoltage. O(avg) • I istheaverageoutputcurrent. O(avg) • I isthequiescentcurrent. (Q) For most TI LDO regulators, the quiescent current is insignificant compared to the average output current; therefore, the term V x I can be neglected. The operating junction temperature is computed by adding the I(avg) (Q) ambient temperature (T ) and the increase in temperature due to the regulator's power dissipation. The A temperature rise is computed by multiplying the maximum expected power dissipation by the sum of the thermal resistances between the junction and the case (RQJC ), the case to heatsink (RQCS ), and the heatsink to ambient (RQSA ). Thermal resistances are measures of how effectively an object dissipates heat. Typically, the larger the device,themoresurfaceareaavailableforpowerdissipationandthelowertheobject'sthermalresistance. Figure 21 illustrates these thermal resistances for (a) a TO-220 package attached to a heatsink, and (b) a TO-263packagemountedonaJEDECHigh-Kboard. C B A TJ A Rq JC A B B TC Rq CS C Rq SA C TO–263 Package TA (b) TO–220 Package (a) Figure21.ThermalResistances 14

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION (continued) Equation2summarizesthecomputation: TJ (cid:2) TA(cid:1)PDmaxx(cid:3)Rq JC (cid:1) Rq CS (cid:1) Rq SA(cid:4) (2) The RQJC is specific to each regulator as determined by its package, lead frame, and die size provided in the regulator's data sheet. The RQSA is a function of the type and size of heatsink. For example, black body radiator type heatsinks, like the one attached to the TO-220 package in Figure 21(a), can have RQCS values ranging from 5(cid:176)C/W for very large heatsinks to 50(cid:176)C/W for very small heatsinks. The RQCS is a function of how the package is attached to the heatsink. For example, if a thermal compound is used to attach a heatsink to a TO-220 package, RQCS of1(cid:176)C/W isreasonable. Even if no external black body radiator type heatsink is attached to the package, the board on which the regulator is mounted will provide some heatsinking through the pin solder connections. Some packages, like the TO-263 and TI's TSSOP PowerPAD™ packages, use a copper plane underneath the package or the circuit board's ground plane for additional heatsinking to improve their thermal performance. Computer aided thermal modeling can be used to compute very accurate approximations of an integrated circuit's thermal performance in different operating environments (e.g., different types of circuit boards, different types and sizes of heatsinks, different air flows, etc.). Using these models, the three thermal resistances can be combined into one thermal resistance between junction and ambient (RQJA ). This RQJA is valid only for the specific operating environment usedinthecomputermodel. Equation2simplifiesintoEquation3: T (cid:2) T (cid:1)P maxx R J A D q JA (3) RearrangingEquation3givesEquation4: T –T R (cid:1) J A q JA P max D (4) Using Equation 3 and the computer model generated curves shown in Figure 22 and Figure 25, a designer can quickly compute the required heatsink thermal resistance/board area for a given ambient temperature, power dissipation,andoperatingenvironment. TO-220 POWER DISSIPATION The TO-220 package provides an effective means of managing power dissipation in through-hole applications. The TO-220 package dimensions are provided in the Mechanical Data section at the end of the data sheet. A heatsinkcanbeusedwiththeTO-220packagetoeffectivelylowerthejunction-to-ambientthermalresistance. To illustrate, the TPS75925 in a TO-220 package was chosen. For this example, the average input voltage is 3.3V,theoutputvoltageis2.5V,theaverageoutputcurrentis3A,theambienttemperature55(cid:176)C, the air flow is 150 LFM, and the operating environment is the same as documented below. Neglecting the quiescent current, themaximumaveragepoweris: P max (cid:1) (3.3–2.5)Vx3A (cid:1) 2.4W D (5) SubstitutingT maxforT intoEquation4givesEquation6: J J Rq JAmax (cid:1) (125–55)°C(cid:2)2.4W (cid:1) 29°C(cid:2)W (6) From Figure 22, RQJA vs Heatsink Thermal Resistance, a heatsink with RQSA = 22(cid:176)C/W is required to dissipate 2.4 W. The model operating environment used in the computer model to construct Figure 22 consisted of a standard JEDEC High-K board (2S2P) with a 1 oz. internal copper plane and ground plane. Since the package pins were soldered to the board, 450 mm2 of the board was modeled as a heatsink. Figure 23 shows the side viewoftheoperatingenvironmentusedinthecomputermodel. 15

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION (continued) 65 Natural Convection W 55 C/ ° − Air Flow = 150 LFM e 45 nc Air Flow = 250 LFM a st Air Flow = 500 LFM esi 35 R al m er 25 h T − A J 15 Rq No Heatsink 5 25 20 15 10 5 0 Rq SA − Heatsink Thermal Resistance − °C/W Figure22.ThermalResistancevsHeatsinkThermalResistance 0.21 mm 0.21 mm 1 oz. Copper 1 oz. Copper Power Plane Ground Plane Figure23. From the data in Figure 22 and rearranging Equation 4, the maximum power dissipation for a different heatsink RQSA andaspecificambienttemperaturecanbecomputed(seeFigure24). 16

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION (continued) 10 TA = 55°C W Air Flow = 500 LFM − mit Air Flow = 250 LFM Li n atio Air Flow = 150 LFM p si s Di er w o P − D P Natural Convection No Heatsink 1 20 10 0 Rq SA − Heatsink Thermal Resistance − °C/W Figure24.PowerDissipationvsHeatsinkThermalResistance The TO-263 package provides an effective means of managing power dissipation in surface mount applications. The TO-263 package dimensions are provided in the Mechanical Data section at the end of the data sheet. The addition of a copper plane directly underneath the TO-263 package enhances the thermal performance of the package. To illustrate, the TPS75925 in a TO-263 package was chosen. For this example, the average input voltage is 3.3V, the output voltage is 2.5 V, the average output current is 3 A, the ambient temperature 55(cid:176)C, the air flow is 150 LFM, and the operating environment is the same as documented below. Neglecting the quiescent current, themaximumaveragepoweris: P max (cid:1) (3.3–2.5)Vx3A (cid:1) 2.4W D (7) SubstitutingT maxforT intoEquation4givesEquation8: J J Rq JAmax (cid:1) (125–55)°C(cid:2)2.4W (cid:1) 29°C(cid:2)W (8) From Figure 25, RQJA vs Copper Heatsink Area, the ground plane needs to be 2 cm2 for the part to dissipate 2.4W. The model operating environment used in the computer model to construct Figure 25 consisted of a standard JEDEC High-K board (2S2P) with a 1 oz. internal copper plane and ground plane. The package is soldered to a 2 oz. copper pad. The pad is tied through thermal vias to the 1 oz. ground plane. Figure 26 shows thesideviewoftheoperatingenvironmentusedinthecomputermodel. 17

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION (continued) 40 No Air Flow W C/ 35 ° − e 150 LFM c n a st 30 si Re 250 LFM al m er 25 h T − A J Rq 20 15 0 0.01 0.1 1 10 100 Copper Heatsink Area − cm2 Figure25.ThermalResistancevsCopperHeatsinkArea 2 oz. Copper Solder Pad with 25 Thermal Vias 1 oz. Copper Power Plane 1 oz. Copper Ground Plane Thermal Vias, 0.3 mm Diameter, 1.5 mm Pitch Figure26. From the data in Figure 25 and rearranging Equation 4, the maximum power dissipation for a different ground planeareaandaspecificambienttemperaturecanbecomputed(seeFigure27). 18

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 THERMAL INFORMATION (continued) 5 TA = 55°C W − n atio 4 250 LFM p si s Di er 150 LFM w 3 o P m u m xi No Air Flow a M 2 − D P 1 0 0.01 0.1 1 10 100 Copper Heatsink Area − cm2 Figure27.MaximumPowerDissipationvsCopperHeatsinkArea 19

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 APPLICATION INFORMATION PROGRAMMING THE TPS75901 ADJUSTABLE LDO REGULATOR The output voltage of the TPS75901 adjustable regulator is programmed using an external resistor divider as showninFigure28.Theoutputvoltageiscalculatedusing: (cid:4) R1(cid:5) VO(cid:3)Vref(cid:1) 1(cid:2)R2 Where: V = 1.224 V typ (the internal reference voltage) ref (9) Resistors R1 and R2 should be chosen for approximately 40-µA divider current. Lower value resistors can be used but offer no inherent advantage and waste more power. Higher values should be avoided as leakage currents at FB increase the output voltage error. The recommended design procedure is to choose R2 = 30.1kW tosetthedividercurrentat40µAandthencalculateR1using: (cid:4)V (cid:5) O R1(cid:3) (cid:2)1 (cid:1)R2 V ref (10) TPS75901 OUTPUT VOLTAGE PROGRAMMING GUIDE VI IN 1 m F OUTPUT ≥ 2 V VOLTAGE R1 R2 UNIT EN OUT VO 2.5 V 31.6 30.1 kW ≤ 0.7 V R1 Co 3.3 V 51 30.1 kW FB 3.6 V 58.3 30.1 kW GND R2 Figure28.TPS75901AdjustableLDORegulatorProgramming REGULATOR PROTECTION The TPS759xx PMOS-pass transistor has a built-in back diode that conducts reverse currents when the input voltage drops below the output voltage (e.g., during power down). Current is conducted from the output to the input and is not internally limited. When extended reverse voltage is anticipated, external limiting may be appropriate. The TPS759xx also features internal current limiting and thermal protection. During normal operation, the TPS759xx limits output current to approximately 10 A. When current limiting engages, the output voltage scales back linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device failure,careshouldbetakennottoexceed the power dissipation ratings of the package. If the temperature of the device exceeds 150(cid:176)C (typ), thermal-protection circuitry shuts it down. Once the device has cooled below 130(cid:176)C (typ),regulatoroperationresumes. INPUT CAPACITOR For a typical application, a ceramic input bypass capacitor (0.22 µF-1 µF) is recommended to ensure device stability.Thiscapacitorshouldbeas close as possible to the input pin. Due to the impedance of the input supply, large transient currents will cause the input voltage to droop. If this droop causes the input voltage to drop below the UVLO threshold, the device will turn off. Therefore, it is recommended that a larger capacitor be placed in parallel with the ceramic bypass capacitor at the regulator's input. The size of this capacitor depends on the output current, response time of the main power supply, and the main power supply's distance to the regulator. At a minimum, the capacitor should be sized to ensure that the input voltage does not drop below the minimum UVLOthresholdvoltageduringnormaloperatingconditions. 20

TPS75901, TPS75915 TPS75918, TPS75925, TPS75933 www.ti.com SLVS318E–DECEMBER2000–REVISEDMARCH2004 APPLICATION INFORMATION (continued) OUTPUT CAPACITOR As with most LDO regulators, the TPS759xx requires an output capacitor connected between OUT and GND to stabilize the internal control loop. The minimum recommended capacitance value is 47 µF with an ESR (equivalent series resistance) of at least 200 mW. As shown in Figure 29, most capacitor and ESR combinations withaproductof47e-6x0.2=9.4e-6orlargerwillbestable, provided the capacitor value is at least 47 µF. Solid tantalum electrolytic and aluminum electrolytic capacitors are all suitable, provided they meet the requirements describedinthissection.Largercapacitorsprovideawiderrangeofstabilityandbetterloadtransientresponse. This information along with the ESR graphs, Figure 19, Figure 20, and Figure 29, is included to assist in selection of suitable capacitance for the user's application. When necessary to achieve low height requirements along with high output current and/or high load capacitance, several higher ESR capacitors can be used in paralleltomeettheseguidelines. 1000 Region of Stability F m− e c n a cit ESR min x Co = Constant pa 100 a C ut p ut 47 O Region of Instability Y = ESRmin x Co 10 0.01 0.1 0.2 ESR − Equivalent Series Resistance − W Figure29.OutputCapacitancevsEquivalentSeriesResistance 21

PACKAGE OPTION ADDENDUM www.ti.com 5-Mar-2004 PACKAGING INFORMATION ORDERABLEDEVICE STATUS(1) PACKAGETYPE PACKAGEDRAWING PINS PACKAGEQTY TPS75901KC ACTIVE TO/SOT KC 5 50 TPS75901KTT OBSOLETE PFM KTT 5 TPS75901KTTR ACTIVE PFM KTT 5 500 TPS75901KTTT ACTIVE PFM KTT 5 50 TPS75915KC ACTIVE TO/SOT KC 5 50 TPS75915KTT OBSOLETE PFM KTT 5 TPS75915KTTR ACTIVE PFM KTT 5 500 TPS75915KTTT ACTIVE PFM KTT 5 50 TPS75918KC ACTIVE TO/SOT KC 5 50 TPS75918KTT OBSOLETE PFM KTT 5 TPS75918KTTR ACTIVE PFM KTT 5 500 TPS75918KTTT ACTIVE PFM KTT 5 50 TPS75925KC ACTIVE TO/SOT KC 5 50 TPS75925KTT OBSOLETE PFM KTT 5 TPS75925KTTR ACTIVE PFM KTT 5 500 TPS75925KTTT ACTIVE PFM KTT 5 50 TPS75933KC ACTIVE TO/SOT KC 5 50 TPS75933KTT OBSOLETE PFM KTT 5 TPS75933KTTR ACTIVE PFM KTT 5 500 TPS75933KTTT ACTIVE PFM KTT 5 50 (1)Themarketingstatusvaluesaredefinedasfollows: ACTIVE:Productdevicerecommendedfornewdesigns. LIFEBUY:TIhasannouncedthatthedevicewillbediscontinued,andalifetime-buyperiodisineffect. NRND:Notrecommendedfornewdesigns.Deviceisinproductiontosupportexistingcustomers,butTIdoesnotrecommendusingthispartin anewdesign. PREVIEW:Devicehasbeenannouncedbutisnotinproduction.Samplesmayormaynotbeavailable. OBSOLETE:TIhasdiscontinuedtheproductionofthedevice.

None

MECHANICAL DATA MSOT008B – JANUARY 1995 – REVISED SEPTEMBER 2000 KC (R-PSFM-T5) PLASTIC FLANGE-MOUNT 0.420 (10,67) 0.113 (2,87) 0.185 (4,70) 0.156 (3,96) DIA 0.380 (9,65) 0.103 (2,62) 0.175 (4,46) 0.146 (3,71) 0.055 (1,40) 0.045 (1,14) 0.147 (3,73) 0.137 (3,48) 0.340 (8,64) 0.330 (8,38) 1.037 (26,34) 0.125 (3,18) 0.997 (25,32) (see Note C) 1 5 0.040 (1,02) 0.122 (3,10) 0.067 (1,70) 0.030 (0,76) 0.102 (2,59) 0.010 (0,25) M 0.268 (6,81) 0.025 (0,64) 0.012 (0,30) 4040208/E 09/00 NOTES: A. All linear dimensions are in inches (millimeters). B. This drawing is subject to change without notice. C. Lead dimensions are not controlled within this area. D. All lead dimensions apply before solder dip. E. The center lead is in electrical contact with the mounting tab. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1

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