LM185-2.5/LM285-2.5/LM385-2.5General DescriptionFeaturesConnection DiagramsAbsolute Maximum RatingsElectrical CharacteristicsElectrical CharacteristicsTypical Performance CharacteristicsApplicationsLM385-2.5 ApplicationsPRECISION 1 μA to 1 mA CURRENT SOURCESMETER THERMOMETERSSchematic DiagramPhysical DimensionsJanuary 30, 2008LM185-2.5/LM285-2.5/LM385-2.5Micropower Voltage Reference DiodeGeneral DescriptionThe LM185-2.5/LM285-2.5/LM385-2.5 are micropower 2-ter-minal band-gap voltage regulator diodes. Operating over a 20μA to 20 mA current range, they feature exceptionally low dy-namic impedance and good temperature stability. On-chiptrimming is used to provide tight voltage tolerance. Since theLM-185-2.5 band-gap reference uses only transistors and re-sistors, low noise and good long term stability result.Careful design of the LM185-2.5 has made the device excep-tionally tolerant of capacitive loading, making it easy to use inalmost any reference application. The wide dynamic operat-ing range allows its use with widely varying supplies withexcellent regulation.The extremely low power drain of the LM185-2.5 makes ituseful for micropower circuitry. This voltage reference can beused to make portable meters, regulators or general purposeanalog circuitry with battery life approaching shelf life. Fur-ther, the wide operating current allows it to replace olderreferences with a tighter tolerance part. For applications re-quiring 1.2V see LM185-1.2.The LM185-2.5 is rated for operation over a −55°C to 125°Ctemperature range while the LM285-2.5 is rated −40°C to 85°C and the LM385-2.5 0°C to 70°C. The LM185-2.5/LM285-2.5are available in a hermetic TO-46 package and theLM285-2.5/LM385-2.5 are also available in a low-cost TO-92molded package, as well as S.O. and SOT-23. TheLM185-2.5 is also available in a hermetic leadless chip carrierpackage.Features■±20 mV (±0.8%) max. initial tolerance (A grade)■Operating current of 20 μA to 20 mA■0.6Ω dynamic impedance (A grade)■Low temperature coefficient■Low voltage reference—2.5V■1.2V device and adjustable device also available—LM185-1.2 series and LM185 series, respectivelyConnection DiagramsTO-92Plastic Package551908Bottom ViewOrder Number LM285Z-2.5,LM285BXZ-2.5, LM285BYZ-2.5LM385Z-2.5, LM385AXZ-2.5LM385AYZ-2.5, LM385BZ-2.5,LM385BXZ-2.5 or LM385BYZ-2.5See NS Package Number Z03ASO Package551911Order Number LM285M-2.5,LM285BXM-2.5, LM285BYM-2.5LM385M-2.5, LM385BM-2.5LM385BXM-2.5 or LM385BYM-2.5See NS Package Number M08ASOT-23551929* Pin 3 is attached to the Die Attach Pad (DAP) and should be connected to Pin 2 or left floating.Order Number LM385M3-2.5See NS Package Number MA03B© 2008 National Semiconductor Corporation 5519 www.national.comLM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference DiodeLCCLeadless Chip Carrier551914Order Number LM185E-2.5/883See NS Package Number E20ATO-46Metal Can Package551913Bottom ViewOrder Number LM185H-2.5,LM185H-2.5/883, LM185BXH-2.5,LM185BXH-2.5/883, LM185BYH-2.5,LM185BYH2.5/883, LM285H-2.5,or LM285BYH-2.5See NS Package Number H02Awww.national.com 2LM185-2.5/LM285-2.5/LM385-2.5Absolute Maximum Ratings (Notes 1, 2)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.Reverse Current 30 mAForward Current 10 mAOperating TemperatureRange (Note 3) LM185-2.5 −55°C to + 125°C LM285-2.5 −40°C to + 85°C LM385-2.5 0°C to 70°CESD Susceptibility (Note 9) 2kVStorage Temperature −55°C to + 150°CSoldering Information TO-92 Package (10 sec.) 260°C TO-46 Package (10 sec.) 300°C SO and SOT Package Vapor Phase (60 sec.) 215°C Infrared (15 sec.) 220°CSee AN-450 “Surface Mounting Methods and Their Effect onProduct Reliability” for other methods of soldering surfacemount devices.Electrical Characteristics(Note 4)Parameter Conditions TypLM385A-2.5Units(Limits)LM385AX-2.5LM385AY-2.5Tested DesignLimit Limit(Note 5) (Note 6)Reverse BreakdownIR = 100 μA2.500 2.480 V(Min)Voltage 2.520 V(Max) 2.500 2.470 V(Min) 2.530 V(Max)Minimum Operating 12 18 20μACurrent (Max)Reverse BreakdownIMIN ≤ IR ≤ 1mA 1 1.5 mVVoltage Change with (Max)Current1 mA ≤ IR ≤ 20 mA 10 20 mV (Max)Reverse DynamicIR = 100 μA,0.2 0.6ΩImpedance f = 20 Hz 1.5 Wideband Noise (rms)IR = 100 μA120 μV 10 Hz ≤ f ≤ 10 kHz Long Term StabilityIR = 100 μA, T = 1000 Hr, 20 ppm TA = 25°C ±0.1°C Average TemperatureIMIN ≤ IR ≤ 20 mA Coefficient (Note 7) X Suffix 30 ppm/°C Y Suffix 50 (Max) All Others 150 3 www.national.comLM185-2.5/LM285-2.5/LM385-2.5Electrical Characteristics LM185-2.5 LM185BX-2.5 LM385B-2.5 LM185BY-2.5 LM385BX-2.5 LM385-2.5 Units LM285-2.5 LM385BY-2.5 (Limit)Parameter Conditions Typ LM285BX-2.5 LM285BY-2.5 Tested Design Tested Design Tested Design Limit Limit Limit Limit Limit Limit (Notes 5, 8) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6) ReverseBreakdownTA = 25°C, 2.5 2.462 2.462 2.425 V(Min)Voltage20 μA ≤ IR ≤ 20 mA 2.538 2.538 2.575 V(Max)Minimum OperatingCurrent 13 20 30 20 30 20 30μA(Max)LM385M3-2.5 15 20ReverseBreakdown VoltageChange withCurrent20 μA ≤ IR ≤ 1 mA 1 1.5 2.0 2.5 2.0 2.5 mV(Max)1 mA ≤ IR ≤ 20 mA 10 20 20 25 20 25 mV(Max)Reverse DynamicIR = 100 μA,1 ΩImpedance f = 20 Hz Wideband Noise(rms)IR = 100 μA,120 μV 10 Hz ≤ f ≤ 10 kHz Long Term StabilityIR = 100 μA, T = 1000 Hr, 20 ppm TA = 25°C ±0.1°C AverageTemperatureIR = 100 μA Coefficient (Note 7) X Suffix 30 30 ppm/°C Y Suffix 50 50 ppm/°C All Others 150 150 150 ppm/°C (Max)Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device isintended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.The guaranteed specifications apply only for the test conditions listed.Note 2: Refer to RETS185H-2.5 for military specifications.Note 3: For elevated temperature operation, TJ MAX is:LM185 150°CLM285 125°CLM385