LM828 Switched Capacitor Voltage Converter datasheet (Rev. D)
Document overview
- Manufacturer or author: Texas Instruments, Incorporated [SNOS035,D]
- PDF pages: 17
Technical content
www.ti.com SNOS035D –MARCH 2010–REVISED MAY 2013 LM828SwitchedCapacitorVoltageConverter Check forSamples: LM828 1FEATURES DESCRIPTION The LM828 CMOS charge-pump voltageconverter 2• InvertsInputSupply Voltage invertsa positivevoltagein the range of +1.8V to• SOT-23 Package +5.5V tothecorrespondingnegativevoltageof−1.8V
- 20Ω TypicalOutput Impedance to−5.5V.The LM828 uses two low costcapacitorsto provideup to25 mA ofoutputcurrent.• 97% TypicalConversion Efficiencyat5 mA The LM828 operatesat 12 kHz switchingfrequency APPLICATIONS to reduce outputresistanceand voltageripple.With an operatingcurrentof only 40 µA (operating• CellularPhones efficiencygreaterthan 96% with most loads),the• Pagers LM828 provides ideal performance for battery
- PDAs powered systems.The deviceis in a tinySOT-23 package.• OperationalAmplifierPower Supplies
- InterfacePower Supplies
- Handheld Instruments Basic ApplicationCircuits VoltageInverter +5V to−10V Converter Pleasebe aware thatan importantnoticeconcerningavailability,standardwarranty,and use incriticalapplicationsof Texas Instrumentssemiconductorproductsand disclaimerstheretoappearsattheend ofthisdatasheet. 2Alltrademarksarethepropertyoftheirrespectiveowners. PRODUCTION DATA informationiscurrentas ofpublicationdate. Copyright© 2010–2013,Texas InstrumentsIncorporatedProductsconform to specificationsper the terms of the Texas Instrumentsstandardwarranty.Productionprocessingdoes not necessarilyincludetestingofallparameters.
SNOS035D –MARCH 2010–REVISED MAY 2013 www.ti.com These deviceshave limitedbuilt-inESD protection.The leadsshouldbe shortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamage totheMOS gates. AbsoluteMaximum Ratings(1)(2) SupplyVoltage(V+ toGND, orGND toOUT) 5.8V V+ and OUT ContinuousOutputCurrent 50 mA OutputShort-CircuitDurationtoGND (3) 1 sec. ContinuousPower Dissipation(TA = 25°C)(4) 240 mW TJMax (4) 150°C θJA (4) 300°C/W OperatingJunctionTemperatureRange −40°C to85°C StorageTemperatureRange −65°C to+150°C Lead Temp. (Soldering,10 seconds) 300°C ESD Rating(5) 2kV (1) Absolutemaximum ratingsindicatelimitsbeyond whichdamage tothedevicemay occur.Electricalspecificationsdo notapplywhen operatingthedevicebeyond itsratedoperatingconditions. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTexas InstrumentsSalesOffice/Distributorsforavailabilityand specifications. (3) OUT may be shortedtoGND forone second withoutdamage. However,shortingOUT toV+ may damage thedeviceand shouldbe avoided.Also,fortemperaturesabove 85°C, OUT must notbe shortedtoGND orV+, orthedevicemay be damaged. (4) The maximum allowablepower dissipationiscalculatedby usingPDMax = (TJMax − TA)/θJA,where TJMax isthemaximum junction temperature,TA istheambienttemperature,and θJA isthejunction-to-ambientthermalresistanceofthepackage. (5) The human body model isa 100 pF capacitordischargedthrougha 1.5kΩ resistorintoeach pin. ElectricalCharacteristics LimitsinstandardtypefaceareforTJ = 25°C, and limitsinboldfacetypeapplyoverthefulloperatingtemperaturerange. Unlessotherwisespecified:V+ = 5V,C 1 = C 2 = 10 μF.(1) Symbol Parameter Condition Min Typ Max Units V+ SupplyVoltage R L =10kΩ 1.8 5.5 V IQ SupplyCurrent No Load 40 75 µA 115 R OUT OutputResistance(2) IL = 5 mA 20 65 Ω fOSC OscillatorFrequency(3) Internal 12 24 56 kHz fSW SwitchingFrequency(3) Measured atCAP+ 6 12 28 kHz PEFF Power Efficiency IL = 5 mA 97 % VOEFF VoltageConversionEfficiency No Load 95 99.96 % (1) Inthetestcircuit,capacitorsC 1 and C 2 are10 µF,0.3Ω maximum ESR capacitors.CapacitorswithhigherESR willincreaseoutput resistance,reduceoutputvoltageand efficiency. (2) Specifiedoutputresistanceincludesinternalswitchresistanceand capacitorESR. See thedetailsintheapplicationinformation. (3) The outputswitchesoperateatone halfoftheoscillatorfrequency,fOSC = 2fSW .
2 SubmitDocumentationFeedback Copyright© 2010–2013,Texas InstrumentsIncorporated
ProductFolderLinks:LM828
www.ti.com SNOS035D –MARCH 2010–REVISED MAY 2013 TestCircuit *C1 and C 2 are10 µF capacitors. Figure1. LM828 TestCircuit TypicalPerformance Characteristics (CircuitofFigure1,V+ = 5V unlessotherwisespecified) Supply Currentvs Supply Currentvs Supply Voltage Temperature Figure2. Figure3. Output Source Resistance Output Source Resistance vs vs Supply Voltage Temperature Figure4. Figure5. Copyright© 2010–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LM828
SNOS035D –MARCH 2010–REVISED MAY 2013 www.ti.com TypicalPerformance Characteristics(continued) (CircuitofFigure1,V+ = 5V unlessotherwisespecified) Output Voltage Efficiencyvs vs Load Current Load Current Figure6. Figure7. SwitchingFrequency vs SwitchingFrequency vs Supply Voltage Temperature Figure8. Figure9. CONNECTION DIAGRAMS 5-Lead SOT-23 Package (DBV) Figure10.SOT-23 Package – Top View Figure11.ActualSize See Package Number DBV0005A
4 SubmitDocumentationFeedback Copyright© 2010–2013,Texas InstrumentsIncorporated
ProductFolderLinks:LM828
www.ti.com SNOS035D –MARCH 2010–REVISED MAY 2013 Pin Functions PIN DESCRIPTIONS Pin Name Function 1 OUT Negativevoltageoutput. 2 V+ Power supplypositiveinput. 3 CAP − Connectthispintothenegativeterminalofthecharge-pumpcapacitor. 4 GND Power supplygroundinput. 5 CAP+ Connectthispintothepositiveterminalofthecharge-pumpcapacitor. CircuitDescription The LM828 containsfourlargeCMOS switcheswhich are switchedina sequence to invertthe inputsupply voltage.Energy transferand storageare providedby externalcapacitors.Figure12 illustratesthe voltage conversionscheme. When S1 and S3 areclosed,C 1 chargestothesupplyvoltageV+. Duringthistimeinterval, switchesS2 and S4 areopen.Inthesecond timeinterval,S1 and S3 areopen;atthesame time,S2 and S4 are closed,C 1 ischargingC 2.Aftera number ofcycles,thevoltageacrossC 2 willbe pumped toV+. Sincetheanode ofC 2 isconnectedtoground,theoutputatthecathodeofC 2 equals−(V+)when thereisno loadcurrent.The outputvoltagedrop when a load isadded isdeterminedby the parasiticresistance(Rds(on) of the MOSFET switchesand theESR ofthecapacitors)and thechargetransferlossbetween capacitors. Figure12. VoltageInvertingPrinciple ApplicationInformation SIMPLE NEGATIVE VOLTAGE CONVERTER The main applicationofLM828 istogeneratea negativesupplyvoltage.The voltageinvertercircuituses only two externalcapacitorsas shown intheBasicApplicationCircuits.The rangeoftheinputsupplyvoltageis1.8V to5.5V. The outputcharacteristicsof thiscircuitcan be approximatedby an idealvoltagesource in serieswitha resistance.The voltagesourceequals−(V+).The outputresistance,R out ,isa functionoftheON resistanceof theinternalMOSFET switches,theoscillatorfrequency,thecapacitanceand theESR ofbothC 1 and C 2.Since theswitchingcurrentchargingand dischargingC 1 isapproximatelytwiceas theoutputcurrent,theeffectofthe ESR ofthepumping capacitorC 1 willbe multipliedby fourintheoutputresistance.The outputcapacitorC 2 is chargingand dischargingata currentapproximatelyequaltotheoutputcurrent,therefore,thisESR term only countsonce intheoutputresistance.A good approximationofR out is: (1) where R SW isthesum oftheON resistanceoftheinternalMOSFET switchesshown inFigure12. Highcapacitance,lowESR capacitorswillreducetheoutputresistance. The peak-to-peakoutputvoltagerippleisdeterminedby theoscillatorfrequency,thecapacitanceand ESR ofthe outputcapacitorC 2: Copyright© 2010–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LM828
SNOS035D –MARCH 2010–REVISED MAY 2013 www.ti.com (2) Again,usinga lowESR capacitorwillresultinlowerripple. CAPACITOR SELECTION The outputresistanceand ripplevoltageare dependent on the capacitanceand ESR valuesof the external capacitors.The outputvoltagedropistheloadcurrenttimestheoutputresistance,and thepower efficiencyis (3) Where IQ (V+)isthequiescentpower lossoftheIC device,and IL 2R out istheconversionlossassociatedwiththe switchon-resistance,thetwo externalcapacitorsand theirESRs. The selectionof capacitorsisbased on the specificationsof the dropoutvoltage(whichequalsIout R out),the outputvoltageripple,and the converterefficiency.Low ESR capacitors(followingtable)are recommended to maximizeefficiency,reducetheoutputvoltagedropand voltageripple. Low ESR CapacitorManufacturers Manufacturer Phone CapacitorType NichiconCorp. (708)-843-7500 PL & PF series,through-holealuminum electrolytic AVX Corp. (803)-448-9411 TPS series,surface-mounttantalum Sprague (207)-324-4140 593D, 594D, 595D series,surface-mounttantalum Sanyo (619)-661-6835 OS-CON series,through-holealuminum electrolytic Murata (800)-831-9172 Ceramicchipcapacitors TaiyoYuden (800)-348-2496 Ceramicchipcapacitors Tokin (408)-432-8020 Ceramicchipcapacitors Other Applications PARALLELING DEVICES Any number of LM828s can be paralleledto reduce the outputresistance.Each devicemust have itsown pumping capacitorC 1, whileonlyone outputcapacitorC out isneeded as shown inFigure13. The composite outputresistanceis: (4) Figure13. Lowering Output Resistanceby ParallelingDevices
6 SubmitDocumentationFeedback Copyright© 2010–2013,Texas InstrumentsIncorporated
ProductFolderLinks:LM828
www.ti.com SNOS035D –MARCH 2010–REVISED MAY 2013 CASCADING DEVICES CascadingtheLM828s isan easy way toproducea greaternegativevoltage(e.g.A two-stagecascade circuitis shown inFigure14). Ifn istheintegerrepresentingthenumber ofdevicescascaded,theunloadedoutputvoltageVout is(-nVin).The effectiveoutputresistanceisequaltotheweightedsum ofeach individualdevice: R out = nR out_1 + n/2R out_2 + ...+ R out_n (5) Thiscan be seen by firstassuming thateach deviceis100 percentefficient.Sincetheoutputvoltageisdifferent on each devicethe outputcurrentisas well.Each cascaded devicesees lesscurrentat the outputthan the previousso theR OUT voltagedropislowerineach deviceadded.Note that,thenumber ofn ispracticallylimited sincethe increasingof n significantlyreducesthe efficiency,and increasesthe outputresistanceand output voltageripple. Figure14. IncreasingOutput Voltageby Cascading Devices COMBINED DOUBLER AND INVERTER InFigure15,theLM828 isused toprovidea positivevoltagedoublerand a negativevoltageconverter.Note that thetotalcurrentdrawn fromthetwo outputsshouldnotexceed 40 mA. Figure15. Combined VoltageDoubler and Inverter Copyright© 2010–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LM828
SNOS035D –MARCH 2010–REVISED MAY 2013 www.ti.com REGULATING VOUT Itispossibleto regulatethe negativeoutputof the LM828 by use of a low dropoutregulator(such as the LP2980).The whole converterisdepictedinFigure16.Thisconvertercan givea regulatedoutputfrom−1.8V to −5.5Vby choosingtheproperresistorratio: Vout= Vref(1+ R 1/R2) (6) where,Vref= 1.23V (7) Note thatthefollowingconditionsmust be satisfiedsimultaneouslyforworstcase design: Vin_min>Vout_min+Vdrop_max (LP2980) (8) + Iout_max × R out_max (LM828) (9) Vin_max < Vout_max +Vdrop_min (LP2980) (10) + Iout_min× R out_min(LM828) (11) Figure16. Combining LM828 withLP2980 toMake a NegativeAdjustableRegulator
8 SubmitDocumentationFeedback Copyright© 2010–2013,Texas InstrumentsIncorporated
ProductFolderLinks:LM828
www.ti.com SNOS035D –MARCH 2010–REVISED MAY 2013
REVISION HISTORY
Changes from RevisionC (May 2013)toRevisionD Page Copyright© 2010–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LM828
www.ti.com 11-Nov-2025 PACKAGING INFORMATION Orderable part number Status (1) Material type (2) Package | Pins Package qty | Carrier RoHS (3) Lead finish/ Ball material (4) MSL rating/ Peak reflow (5) Op temp (°C) Part marking (6) LM828M5/NOPB Active Production SOT-23 (DBV) | 5 1000 | SMALL T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A LM828M5/NOPB.A Active Production SOT-23 (DBV) | 5 1000 | SMALL T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A LM828M5/NOPB.B Active Production SOT-23 (DBV) | 5 1000 | SMALL T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A LM828M5X/NOPB Active Production SOT-23 (DBV) | 5 3000 | LARGE T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A LM828M5X/NOPB.A Active Production SOT-23 (DBV) | 5 3000 | LARGE T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A LM828M5X/NOPB.B Active Production SOT-23 (DBV) | 5 3000 | LARGE T&R Yes SN Level-1-260C-UNLIM -40 to 85 S08A (1) Status: For more details on status, see our product life cycle. (2) Material type: When designated, preproduction parts are prototypes/experimental devices, and are not yet approved or released for full production. Testing and final process, including without limitation quality assurance, reliability performance testing, and/or process qualification, may not yet be complete, and this item is subject to further changes or possible discontinuation. If available for ordering, purchases will be subject to an additional waiver at checkout, and are intended for early internal evaluation purposes only. These items are sold without warranties of any kind. (3) RoHS values: Yes, No, RoHS Exempt. See the TI RoHS Statement for additional information and value definition. (4) Lead finish/Ball material: Parts may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. (5) MSL rating/Peak reflow: The moisture sensitivity level ratings and peak solder (reflow) temperatures. In the event that a part has multiple moisture sensitivity ratings, only the lowest level per JEDEC standards is shown. Refer to the shipping label for the actual reflow temperature that will be used to mount the part to the printed circuit board. (6) Part marking: There may be an additional marking, which relates to the logo, the lot trace code information, or the environmental category of the part. Multiple part markings will be inside parentheses. Only one part marking contained in parentheses and separated by a "~" will appear on a part. If a line is indented then it is a continuation of the previous line and the two combined represent the entire part marking for that device. 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. Addendum-Page 1
www.ti.com 11-Nov-2025 Addendum-Page 2
PACKAGE MATERIALS INFORMATION www.ti.com 5-Sep-2025 TAPE AND REEL INFORMATION Reel Width (W1) REEL DIMENSIONS A0B0K0WDimension designed to accommodate the component lengthDimension designed to accommodate the component thicknessOverall width of the carrier tapePitch between successive cavity centersDimension designed to accommodate the component width TAPE DIMENSIONSK0 P1B0WA0Cavity QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE Pocket QuadrantsSprocket HolesQ1Q1Q2Q2Q3Q3Q4Q4User Direction of Feed P1ReelDiameter *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Reel Diameter (mm) Reel Width W1 (mm) (mm) (mm) (mm) (mm) W (mm) Pin1 Quadrant Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION www.ti.com 5-Sep-2025 TAPE AND REEL BOX DIMENSIONS Width (mm) W LH *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM828M5/NOPB SOT-23 DBV 5 1000 208.0 191.0 35.0 LM828M5X/NOPB SOT-23 DBV 5 3000 208.0 191.0 35.0 Pack Materials-Page 2
www.ti.com PACKAGE OUTLINE C 0.22
0.08 TYP
0.25 3.0 2.6 2X 0.95 1.9 1.45 0.90 0.15
0.00 TYP
5X 0.5 0.3 0.6
0.3 TYP
0 TYP
1.9 (0.1) (0.15) 4X 0 -15 4X 4 -15 A 3.05 2.75 B1.75 1.45 (1.1) SOT-23 - 1.45 mm max heightDBV0005A SMALL OUTLINE TRANSISTOR 4214839/K 08/2024 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. Refernce JEDEC MO-178. 4. Body dimensions do not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.25 mm per side. 5. Support pin may differ or may not be present.
0.2 C A B
0.1 C SCALE 4.000
www.ti.com EXAMPLE BOARD LAYOUT
0.07 MAX
0.07 MIN
5X (1.1) 5X (0.6) (2.6) (1.9) 2X (0.95) (R0.05) TYP 4214839/K 08/2024 SOT-23 - 1.45 mm max heightDBV0005A SMALL OUTLINE TRANSISTOR 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. SYMM LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:15X PKG 3 4 SOLDER MASK OPENING METAL UNDER SOLDER MASK SOLDER MASK DEFINED EXPOSED METAL METALSOLDER MASK OPENING NON SOLDER MASK DEFINED (PREFERRED) SOLDER MASK DETAILS EXPOSED METAL
www.ti.com EXAMPLE STENCIL DESIGN (2.6) (1.9) 2X(0.95) 5X (1.1) 5X (0.6) (R0.05) TYP SOT-23 - 1.45 mm max heightDBV0005A SMALL OUTLINE TRANSISTOR 4214839/K 08/2024 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. SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE:15X SYMM PKG 3 4
IMPORTANT NOTICE AND DISCLAIMER 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, regulatory 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 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, TI’s General Quality Guidelines, 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. Unless TI explicitly designates a product as custom or customer-specified, TI products are standard, catalog, general purpose devices. TI objects to and rejects any additional or different terms you may propose. IMPORTANT NOTICE Copyright © 2025, Texas Instruments Incorporated Last updated 10/2025