LM431 PDF

LM431Adjustable Precision Zener Shunt RegulatorGeneral DescriptionThe LM431is a 3-terminal adjustable shunt regulator with guaranteed temperature stability over the entire temperature range of operation.It is now available in a chip sized pack-age (4-Bump micro SMD)using National’s micro SMD pack-age technology.The output voltage may be set at any level greater than 2.5V (V REF )up to 36V merely by selecting two external resistors that act as a voltage divided network.Due to the sharp turn-on characteristics this device is an excel-lent replacement for many zener diode applications.Featuresn Average temperature coefficient 50ppm/˚Cn Temperature compensated for operation over the full temperature rangen Programmable output voltage n Fast turn-on response n Low output noisen LM431in micro SMD packagen See AN-1112for micro SMD considerationsConnection DiagramsNote:*NC =Not internally connected.Must be electrically isolated from therest of the circuit for the microSMD package.TO-92:Plastic PackageDS010055-1Top ViewSO-8:8-Pin Surface MountDS010055-2Top viewSOT-23:3-Lead Small OutlineDS010055-28Top View 4-Bump micro SMDDS010055-54Top View(bump side down)March 2002LM431Adjustable Precision Zener Shunt Regulator©2002National Semiconductor Corporation Ordering InformationPackage Typical Accuracy Order Number/Package MarkingTemperature Range Transport MediaNSC Drawing0.5%1%2%TO-92LM431CCZ/LM431CCZ LM431BCZ/LM431BCZ LM431ACZ/LM431ACZ 0˚C to +70˚CRailsZ03ALM431CIZ/LM431CIZLM431BIZ/LM431BIZ LM431AIZ/LM431AIZ −40˚C to +85˚C SO-8LM431CCM/431CCM LM431BCM/431BCM LM431ACM/LM431ACM 0˚C to +70˚CRails and Tape &ReelM08A LM431CIM/431CIMLM431BIM/431BIM LM431AIM/LM431AIM −40˚C to +85˚C SOT-23LM431CCM3/N1B LM431BCM3/N1D LM431ACM3/N1F 0˚C to +70˚CRails and Tape &ReelMF03A LM431CIM3N1ALM431BIM3N1CLM431AIM3N1E−40˚C to +85˚C micro SMD––LM431AIBPLM431AIBPX(Note 1)−40˚C to +85˚C250Units Tape and Reel3k Units Tape and ReelBPA04AFBNote 1:The micro SMD package marking is a 1digit manufacturing Date Code onlymicro SMD Top View Marking ExampleDS010055-56L M 431 2Symbol and Functional DiagramsDC Test CircuitsDS010055-99DS010055-55DS010055-4FIGURE 1.Test Circuit for V Z =V REFDS010055-5Note:V Z =V REF (1+R1/R2)+I REF •R1FIGURE 2.Test Circuit for V Z >V REFDS010055-6FIGURE 3.Test Circuit for Off-State CurrentLM4313Absolute Maximum Ratings (Note 2)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.Storage Temperature Range −65˚C to +150˚C Operating Temperature Range Industrial (LM431xI)−40˚C to +85˚C Commercial (LM431xC)0˚C to +70˚C Soldering InformationInfrared or Convection (20sec.)235˚CWave Soldering (10sec.)260˚C (lead temp.)Cathode Voltage37VContinuous Cathode Current−10mA to +150mAReference Voltage−0.5V Reference Input Current10mA Internal Power Dissipation (Notes 3,4)TO-92Package SO-8Package SOT-23Package 0.78W 0.81W 0.28W micro SMD Package0.30WOperating ConditionsMin Max Cathode Voltage V REF 37V Cathode Current1.0mA100mALM431Electrical CharacteristicsT A =25˚C unless otherwise specified Symbol ParameterConditionsMin Typ Max Units V REFReference VoltageV Z =V REF ,I I =10mA 2.4402.4952.550VLM431A (Figure 1)V Z =V REF ,I I =10mA 2.4702.4952.520VLM431B (Figure 1)V Z =V REF ,I I =10mA 2.4852.5002.510VLM431C (Figure 1)V DEVDeviation of Reference Input Voltage Over V Z =V REF ,I I =10mA,8.017mVTemperature (Note 5)T A =Full Range (Figure 1)Ratio of the Change in Reference Voltage I Z =10mAV Z from V REF to 10V −1.4−2.7mV/Vto the Change in Cathode Voltage(Figure 2)V Z from 10V to 36V−1.0−2.0I REF Reference Input CurrentR 1=10k Ω,R 2=∞, 2.04.0µA I I =10mA (Figure 2)∝I REFDeviation of Reference Input Current over R 1=10k Ω,R 2=∞,TemperatureI I =10mA,0.4 1.2µA T A =Full Range (Figure 2)I Z(MIN)Minimum Cathode Current for Regulation V Z =V REF (Figure 1)0.4 1.0mA I Z(OFF)Off-State CurrentV Z =36V,V REF =0V (Figure 3)0.31.0µA r ZDynamic Output Impedance (Note 6)V Z =V REF ,LM431A,0.75ΩFrequency =0Hz (Figure 1)V Z =V REF ,LM431B,LM431C 0.50ΩFrequency =0Hz (Figure 1)Note 2:Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Electrical specifications do not apply when operating the device beyond its rated operating conditions.Note 3:T J Max =150˚C.Note 4:Ratings apply to ambient temperature at 25˚C.Above this temperature,derate the TO-92at 6.2mW/˚C,the SO-8at 6.5mW/˚C,the SOT-23at 2.2mW/˚C and the micro SMD at 3mW/˚C.Note 5:Deviation of reference input voltage,V DEV ,is defined as the maximum variation of the reference input voltage over the full temperature range.L M 431 4LM431Electrical Characteristics(Continued)Where:T 2−T 1=full temperature change (0-70˚C).∝V REF can be positive or negative depending on whether the slope is positive or negative.Example:V DEV =8.0mV,V REF =2495mV,T 2−T 1=70˚C,slope is positive.Note 6:The dynamic output impedance,r Z ,is defined as:When the device is programmed with two external resistors,R1and R2,(see Figure 2),the dynamic output impedance of the overall circuit,r Z ,is defined as:Equivalent CircuitDS010055-7The average temperature coefficient of the reference input voltage,∝V REF ,is defined as:DS010055-3LM4315Typical Performance CharacteristicsInput Current vs V ZDS010055-29Thermal InformationDS010055-30Input Current vs V ZDS010055-31Dynamic Impedance vs FrequencyDS010055-9DS010055-10Stability Boundary ConditionsDS010055-11Note:The areas under the curves represent conditions that may cause the device to oscillate.For curves B,C,and D,R2and V +were adjusted to establish the initial V Z and I Z conditions with C L =0.V +and C L were then adjusted to determine the ranges of stability.Test Circuit for Curve A Above DS010055-12Test Circuit for Curves B,C and D AboveDS010055-13L M 431 6Typical ApplicationsShunt RegulatorDS010055-14Single Supply Comparator withTemperature Compensated ThresholdDS010055-15Series RegulatorDS010055-16Output Control of a ThreeTerminal Fixed RegulatorDS010055-17Higher Current Shunt RegulatorDS010055-18Crow BarDS010055-19LM4317Typical Applications(Continued)Over Voltage/Under VoltageProtection CircuitDS010055-20Voltage MonitorDS010055-21L M 431 8Typical Applications(Continued)Application Info1.0MountingTo ensure that the geometry of the micro SMD packagemaintains good physical contact with the printed circuitboard,pin A1(NC)must be soldered to the pcb.Please seeAN-1112for more detailed information regarding boardmounting techniques for the micro SMD package.2.0LM431micro SMD Light SensitivityWhen the LM431micro SMD package is exposed to brightsunlight,normal office fluorescent light,and other LED’s andlasers,it operates within the guaranteed limits specified inthe electrical characteristics table.Delay TimerDS010055-22Current Limiter or Current SourceDS010055-23Constant Current SinkDS010055-24LM4319Physical Dimensionsinches (millimeters)unless otherwise notedNS Package Number M08ASOT-23Molded Small Outline Transistor Package (M3)NS Package Number MF03AL M 431 10LM431 Physical Dimensions inches(millimeters)unless otherwise noted(Continued)11Physical Dimensions inches(millimeters)unless otherwise noted(Continued)LIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION.As used herein:1.Life support devices or systems are devices orsystems which,(a)are intended for surgical implantinto the body,or(b)support or sustain life,andwhose failure to perform when properly used inaccordance with instructions for use provided in thelabeling,can be reasonably expected to result in asignificant injury to the user.2.A critical component is any component of a lifesupport device or system whose failure to performcan be reasonably expected to cause the failure ofthe life support device or system,or to affect itssafety or effectiveness.National SemiconductorCorporationAmericasEmail:support@National SemiconductorEuropeFax:+49(0)180-5308586Email:europe.support@Deutsch Tel:+49(0)6995086208English Tel:+44(0)8702402171Français Tel:+33(0)141918790National SemiconductorAsia Pacific CustomerResponse GroupTel:65-2544466Fax:65-2504466Email:ap.support@National SemiconductorJapan Ltd.Tel:81-3-5639-7560Fax:81-3-5639-7507 NOTES:UNLESS OTHERWISE SPECIFIED1.EPOXY COATING2.63Sn/37Pb EUTECTIC BUMP3.RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.4.PIN A1IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION.REMAINING PINS ARENUMBERED.5.XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1IS PACKAGE WIDTH,X2ISPACKAGE LENGTH AND X3IS PACKAGE HEIGHT.6.REFERENCE JEDEC REGISTRATION MO-211,VARIATION BA.4-Bump micro SMDX1=0.777X2=0.904X3=0.850NS Package Number BPA04AFBLM431AdjustablePrecisionZenerShuntRegulatorNational does not assume any responsibility for use of any circuitry described,no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.。