LM2940/LM2940CGeneral DescriptionFeaturesTypical ApplicationOrdering InformationConnection DiagramsAbsolute Maximum RatingsOperating Conditions Electrical CharacteristicsElectrical CharacteristicsElectrical CharacteristicsThermal PerformanceTypical Performance CharacteristicsEquivalent Schematic DiagramApplication HintsEXTERNAL CAPACITORSFIGURE 1. ESR Limits HEATSINKINGFIGURE 2. Power Dissipation Diagram HEATSINKING TO-220 PACKAGE PARTSHEATSINKING TO-263 AND SOT-223 PACKAGE PARTSFIGURE 3. (JA) vs. Copper (1 ounce) Area for the TO-263 Package FIGURE 4. Maximum Power Dissipation vs. TAMB for the TO-263 Package FIGURE 5. (JA) vs. Copper (2 ounce) Area for the SOT-223 Package FIGURE 6. Maximum Power Dissipation vs. TAMB for the SOT-223 Package Physical DimensionsLM2940/LM2940C1A Low Dropout RegulatorGeneral DescriptionThe LM2940/LM2940C positive voltage regulator featuresthe ability to source 1A of output current with a dropoutvoltage of typically 0.5V and a maximum of 1V over theentire temperature range. Furthermore, a quiescent currentreduction circuit has been included which reduces theground current when the differential between the input volt-age and the output voltage exceeds approximately 3V. Thequiescent current with 1A of output current and an input-output differential of 5V is therefore only 30 mA. Higherquiescent currents only exist when the regulator is in thedropout mode (VIN−VOUT≤ 3V).Designed also for vehicular applications, the LM2940/LM2940C and all regulated circuitry are protected from re-verse battery installations or 2-battery jumps. During linetransients, such as load dump when the input voltage canmomentarily exceed the specified maximum operating volt-age, the regulator will automatically shut down to protectboth the internal circuits and the load. The LM2940/LM2940C cannot be harmed by temporary mirror-image in-sertion. Familiar regulator features such as short circuit andthermal overload protection are also provided.Featuresn Dropout voltage typically 0.5V@IO=1An Output current in excess of 1An Output voltage trimmed before assemblyn Reverse battery protectionn Internal short circuit current limitn Mirror image insertion protectionn P+Product Enhancement testedTypical Application00882203*Required if regulator is located far from power supply filter.**COUTmust be at least 22 µF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possibleto the regulator. This capacitor must be rated over the same operating temperature range as the regulator and the ESR is critical; see curve.Ordering InformationTemperatureRangeOutput VoltagePackage5.0 8.0 9.0 10 12 150˚C ≤ TJ≤ 125˚C LM2940CT-5.0 LM2940CT-9.0 LM2940CT-12 LM2940CT-15 TO-220LM2940CS-5.0 LM2940CS-9.0 LM2940CS-12 LM2940CS-15 TO-263−40˚C ≤ TJ≤125˚CLM2940LD-5.0 LM2940LD-8.0 LM2940LD-9.0 LM2940LD-10 LM2940LD-12 LM2940LD-15 LLP 1kUnitsTape andReelLM2940LDX-5.0 LM2940LDX-8.0 LM2940LDX-9.0 LM2940LDX-10 LM2940LDX-12 LM2940LDX-15 LLP 4.5kUnitsTape andReel−40˚C ≤ TJ≤125˚CLM2940T-5.0 LM2940T-8.0 LM2940T-9.0 LM2940T-10 LM2940T-12 TO-220LM2940S-5.0 LM2940S-8.0 LM2940S-9.0 LM2940S-10 LM2940S-12 TO-263−40˚C ≤ TJ≤85˚CLM2940IMP-5.0 LM2940IMP-8.0 LM2940IMP-9.0 LM2940IMP-10 LM2940IMP-12 LM2940IMP-15 SOT-223LM2940IMPX-5.0 LM2940IMPX-8.0 LM2940IMPX-9.0 LM2940IMPX-10 LM2940IMPX-12 LM2940IMPX-15 SOT-223in Tapeand ReelSOT-223Package MarkingL53B L54B L0EB L55B L56B L70BThe physical size of the SOT-223 is too small to contain the full device part number. The package markings indicated are what will appear on the actual device.January 2003LM2940/LM2940C 1A Low Dropout Regulator© 2003 National Semiconductor Corporation DS008822 www.national.comOrdering Information (Continued)TemperatureRangeOutput Voltage Package5.0 8.0 12 15−55˚C ≤ TJ≤ 125˚C LM2940J-5.0/8835962-8958701EALM2940J-8.0/8835962-9088301QEALM2940J-12/8835962-9088401QEALM2940J-15/8835962-9088501QEAJ16ALM2940WG5.0/8835962-8958701XAWG16AFor information on military temperature range products, please go to the Mil/Aero Web Site at http://www.national.com/appinfo/milaero/index.html.Connection Diagrams(TO-220) Plastic Package 3-Lead SOT-22300882202Front ViewOrder Number LM2940CT-5.0, LM2940CT-9.0,LM2940CT-12, LM2940CT-15, LM2940T-5.0,LM2940T-8.0, LM2940T-9.0,LM2940T-10 or LM2940T-12See NS Package Number TO3B00882242Front ViewOrder Part Number LM2940IMP-5.0,LM2940IMP-8.0, LM2940IMP-9.0,LM2940IMP-10, LM2940IMP-12 or LM2940IMP-15See NS Package Number MP04A16-Lead Dual-in-Line Package (J)00882243Top ViewOrder Number LM2940J-5.0/883 (5962-8958701EA),LM2940J-8.0/883 (5962-9088301QEA),LM2940J-12/883 (5962-9088401QEA),LM2940J-15/883 (5962-9088501QEA)See NS Package Number J16A16-Lead Ceramic Surface-Mount Package (WG)00882244Top ViewOrder Number LM2940WG5.0/883 (5962-8958701XA)See NS Package Number WG16ALM2940/LM2940Cwww.national.com 2Connection Diagrams (Continued)(TO-263) Surface-Mount Package00882211Top View8-Lead LLP00882246Top ViewOrder Number LM2940LD-5.0, LM2940LD-8.0,LM2940LD-9.0, LM2940LD-10,LM2940LD-12, LM2940LD-15See NS Package Number LDC08APin 2 and pin 7 are fused to center DAPPin 5 ans 6 need to be tied together on PCB board00882212Side ViewOrder Number LM2940CS-5.0, LM2940CS-9.0,LM2940CS-12, LM2940CS-15,LM2940S-5.0, LM2940S-8.0,LM2940S-9.0, LM2940S-10 or LM2940S-12See NS Package Number TS3BLM2940/LM2940Cwww.national.com3Absolute Maximum Ratings (Note 1)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.LM2940S, T, MP ≤ 100 ms 60VLM2940CS, T ≤ 1 ms 45VInternal Power Dissipation(Note 2) Internally LimitedMaximum Junction Temperature 150˚CStorage Temperature Range −65˚C ≤ TJ≤ +150˚CLead Temperature, Time for Wave SolderingTO-220 (T) Package 260˚C, 10sTO-263 (S) Package 260˚C, 4sSOT-223 (MP) Package 260˚C, 4sESD Susceptibility (Note 3) 2 kVOperating Conditions (Note 1)Input Voltage 26VTemperature RangeLM2940T, LM2940S −40˚C ≤ TJ≤ 125˚CLM2940CT, LM2940CS 0˚C ≤ TJ≤ 125˚CLM2940IMP −40˚C ≤ TJ≤ 85˚CLM2940J, LM2940WG −55˚C ≤ TJ≤ 125˚CLM2940LD −40˚C ≤ TJ≤ 125˚CElectrical CharacteristicsVIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera-ture range of the indicated device. All other specifications apply for TA=TJ= 25˚C.Output Voltage (VO)5V 8VUnitsLM2940 LM2940/883
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