LM1815 Adaptive Variable Reluctance Sensor Amplifier (Rev. F)
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- Manufacturer or author: Texas Instruments, Incorporated [SNOSBU8,F]
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www.ti.com SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 LM1815AdaptiveVariableReluctanceSensorAmplifier Check forSamples: LM1815 1FEATURES DESCRIPTION The LM1815 is an adaptivesense amplifierand 2• AdaptiveHysteresis defaultgatingcircuitformotor controlapplications.• SingleSupply Operation The sense amplifierprovidesa one-shotpulseoutput
- Ground Referenced Input whose leadingedge coincideswith the negative- going zero crossingof a ground referencedinput• True Zero Crossing Timing Reference signalsuch as from a variablereluctancemagnetic• Operates from 2V to12V Supply Voltage pick-upcoil.
- Handles Inputsfrom 100 mV P-P toover 120VP-P In normal operation,thistimingreferencesignaliswithExternalResistor processed (delayed)externallyand returnedto the• CMOS Compatible Logic LM1815. A Logicinputisthen able to selecteither the timingreferenceor the processed signalfor APPLICATIONS transmissiontotheoutputdriverstage.
- PositionSensing withNotched Wheels The adaptivesense amplifieroperateswitha positive- going thresholdwhich isderivedby peak detecting• Zero Crossing Switch theincomingsignaland dividingthisdown. Thus the• Motor Speed Control inputhysteresisvarieswithinputsignalamplitude.• Tachometer Thisenablesthe circuitto sense insituationswhere
- Engine Testing the highspeed noiseisgreaterthan the low speed signalamplitude.Minimum inputsignalis150mV P-P. Connection Diagram Figure1. Top View 14-Lead SOIC or PDIP See D or NFF0014A Package These deviceshave limitedbuilt-inESD protection.The leadsshouldbe shortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamage totheMOS gates. Pleasebe aware thatan importantnoticeconcerningavailability,standardwarranty,and use incriticalapplicationsof Texas Instrumentssemiconductorproductsand disclaimerstheretoappearsattheend ofthisdatasheet. 2Alltrademarksarethepropertyoftheirrespectiveowners. PRODUCTION DATA informationiscurrentas ofpublicationdate. Copyright© 2000–2013,Texas InstrumentsIncorporatedProductsconform to specificationsper the terms of the Texas Instrumentsstandardwarranty.Productionprocessingdoes not necessarilyincludetestingofallparameters.
SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 www.ti.com AbsoluteMaximum Ratings(1)(2) SupplyVoltage 12V Power Dissipation(3) 1250 mW OperatingTemperatureRange −40°C ≤ TA ≤ +125°C StorageTemperatureRange −65°C ≤ TJ ≤ +150°C JunctionTemperature +150°C InputCurrent ±30 mA Lead Temperature(Soldering,10 sec.) 260°C (1) “AbsoluteMaximum Ratings”arethosevaluesbeyond whichthesafetyofthedevicecannotbe ensured.They arenotmeant toimply thatthedevicesshouldbe operatedattheselimits.The tableof“ElectricalCharacteristics”specifiesconditionsofdeviceoperation. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTexas InstrumentsSalesOffice/Distributorsforavailabilityand specifications. (3) Foroperationatelevatedtemperatures,thedevicemust be deratedbased on a 150°C maximum junctiontemperatureand a thermal resistanceof80°C/W (DIP),120°C/W (SO-14)junctiontoambient. ElectricalCharacteristics (TA = 25°C, VCC = 10V,unlessotherwisespecified,see Figure17) Parameter Conditions Min Typ Max Units OperatingSupplyVoltage 2.5 10 12 V SupplyCurrent Pin3 = -0.1V,Pin9 = 2V,Pin11 = 0.8V 3.6 6 mA ReferencePulseWidth fIN = 1Hz to2kHz,R = 150kΩ,C = 0.001µF 70 100 130 µs LogicInputBiasCurrent VIN = 2V,(Pin9 and Pin11) 5 µA SignalInputBiasCurrent VIN = 0V dc,(Pin3) -200 nA LogicThreshold (Pin9 and Pin11) 0.8 1.1 2.0 V VOUT High R L = 1kΩ,(Pin10) 7.5 8.6 V VOUT Low ISINK = 0.1mA,(Pin10) 0.3 0.4 V OutputLeakage Pin12 V12 = 11V 0.01 10 µA SaturationVoltageP12 I12 = 2mA 0.2 0.4 V InputZeroCrossingThreshold AllModes, VSIGNAL = 1V pk-pk -25 0 25 mV (1) Mode 1,Pin5 = Open 30 45 60 mV (1) Minimum InputArmingThreshold Mode 2,Pin5 = VCC 200 300 450 mV (1) Mode 3,Pin5 = Gnd -25 0 25 mV (1) Mode 1,Pin5 = Open 40 80 90 % (1) VSIGNAL ≥ 230mV pk-pk(2) Mode 2,Pin5 = VCCAdaptiveInputArmingThreshold 80 % (1) VSIGNAL ≥ 1.0Vpk-pk(2) Mode 3,Pin5 = Gnd 80 % (1) VSIGNAL ≥ 150mV pk-pk(2) (1) The Min/TypMax limitsarerelativetothepositivevoltagepeak seen atVIN Pin3. (2) TestedperFigure17,VSIGNAL isa SineWave; FSIGNAL is1000Hz.
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www.ti.com SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 TypicalPerformance Characteristics Mode 1 Minimum Arming Threshold Mode 2 Minimum Arming Threshold vs Temperature vs Temperature Figure2. Figure3. Mode 3 Minimum Arming Threshold vs Temperature Mode 1 Minimum Arming Thresholdvs VCC Figure4. Figure5. Mode 2 Minimum Arming Thresholdvs VCC Pin 3 VIN vs VSIGNAL Figure6. Figure7. Copyright© 2000–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LM1815
SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 www.ti.com TypicalPerformance Characteristics(continued) Pin 3 VIN vs VSIGNAL ,R IN = 10kΩ Pin 3 VIN vs VSIGNAL ,R IN = 20kΩ Figure8. Figure9. Pin 3 VIN vs VSIGNAL ,R IN = 50kΩ Pin 3 Bias Currentvs Temperature Figure10. Figure11. Peak DetectorCharge Current vs Temperature Peak DetectorCharge Currentvs VCC Figure12. Figure13.
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www.ti.com SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 TypicalPerformance Characteristics(continued) Peak DetectorVoltage Peak DetectorVoltage vs Pin 3 VIN,Mode 1 vs Pin 3 VIN,Mode 2 Figure14. Figure15. Peak DetectorVoltage vs Pin 3 VIN,Mode 3 Figure16. Copyright© 2000–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LM1815
SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 www.ti.com TRUTH TABLE SignalInput RC Timing InputSelect Timing Input Gated Output Pin 3 Pin 14 Pin 11 Pin 9 Pin 10 ± Pulses RC L X Pulses= RC X X H H H X X H L L ± Pulses L L L ZeroCrossing Figure17. LM1815 AdaptiveSense Amplifier
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www.ti.com SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 Schematic Diagram Copyright© 2000–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LM1815
SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 www.ti.com APPLICATION HINTS Figure18. LM1815 Oscillograms INPUT VOLTAGE CLAMP The signalinputvoltageatpin3 isinternallyclamped.CurrentlimitfortheInputpinisprovidedby an external resistorwhich shouldbe selectedto allowa peak currentof ±3 mA innormal operation.Positiveinputsare clamped by a 1kΩ resistorand seriesdiode(seeR4 and Q12 intheinternalschematicdiagram),whilean active clamp limitspin3 totypically350mV below Ground fornegativeinputs(seeR2, R3, Q10, and Q11 intheinternal schematicdiagram).Thus forinputsignaltransitionsthatare more than 350mV below Ground, the inputpin current(up to 3mA) willbe pulledfrom the V+ supply.Ifthe V+ pinisnot adequatelybypassed the resulting voltagerippleat the V+ pinwilldisruptnormal deviceoperation.Likewise,forinputsignaltransitionsthatare more than500mV above Ground,theinputpincurrentwillbe dumped toGround throughdevicepin2.Slight shiftsin the Ground potentialat devicepin 2, due to poor groundingtechniquesrelativeto the inputsignal ground,can cause unreliableoperation.As always,adequatedevicegrounding,and V+ bypassing,needs tobe consideredacrosstheentireinputvoltageand frequencyrangefortheintendedapplication. INPUT CURRENT LIMITING As statedearlier,currentlimitingfortheInputpinisprovidedby a usersuppliedexternalresistor.Forpurposesof selectingthe appropriateresistorvaluethe Inputpin shouldbe consideredto be a zero ohm connectionto ground.For applicationswhere theinputvoltagesignalisnotsymmetricalwithrelationshiptoGround theworst case voltagepeak shouldbe used. Minimum Rext= [(Vinpeak)/3mA] Intheapplicationexample shown inFigure17 (Rext= 18kΩ)therecommended maximum inputsignalvoltageis ±54V (i.e.108Vp-p). OPERATION OF ZERO CROSSING DETECTOR The LM1815 isdesignedtooperateas a zerocrossingdetector,triggeringan internalone shoton thenegative- goingedge oftheinputsignal.Unlikeotherzerocrossingdetectors,theLM1815 cannotbe triggereduntilthe inputsignalhas crossedan "arming"thresholdon thepositive-goingportionofthewaveform.The armingcircuit isresetwhen the chipistriggered,and subsequentzero crossingsare ignoreduntilthe arming thresholdis exceeded again.Thisthresholdvariesdependingon theconnectionatpin5.Three differentmodes ofoperation arepossible:
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www.ti.com SNOSBU8F –SEPTEMBER 2000–REVISED MARCH 2013 MODE 1,PIN 5 OPEN The adaptivemode isselectedby leavingdevicepin5 open circuit.For inputsignalsoflessthan±135mV (i.e. 270 mVp-p) and greaterthantypically±75mV (i.e.150mVp-p),theinputarmingthresholdistypicallyat45mV. Under theseconditionstheinputsignalmust firstcrossthe45mV thresholdinthepositivedirectiontoarm the zerocrossingdetector,and thencrosszerointhenegativedirectiontotriggerit. Ifthesignalislessthan30mV peak (minimum ratinginElectricalCharacteristics),theone shotisensuredtonot trigger. Inputsignalsof greaterthan±230mV (i.e.460 mVp-p) willcause the arming thresholdto trackat 80% of the peak inputvoltage.A peak detectorcapacitoratdevicepin7 storesa valuerelativetothepositiveinputpeaks to establishthearmingthreshold.Inputsignalsmust exceed thisthresholdinthepositivedirectiontoarm thezero crossingdetector,whichcan thenbe triggeredby a negative-goingzerocrossing. The peak detectortracksrapidlyas the inputsignalamplitudeincreases,and decays by virtueof the resistor connectedexternallyatpin7 trackdecreasesintheinputsignal. Iftheinputsignalamplitudefallsfasterthanthevoltagestoredon thepeak detectorcapacitortheremay be a lossofoutputsignaluntilthecapacitorvoltagehas decayed toan appropriatelevel. Note thatsincetheinputvoltageisclamped,thewaveform observedatpin3 isnotidenticaltothewaveform observedat the variablereluctancesensor.Similarly,the voltagestoredat pin7 isnot identicalto the peak voltageappearingatpin3. MODE 2,PIN 5 CONNECTED TO V+ The inputarmingthresholdisfixedat200mV minimum when devicepin5 isconnectedtothepositivesupply. The chiphas no outputforsignalsoflessthan±200 mV (i.e.400mVp-p) and triggerson thenextnegative-going zerocrossingwhen thearmingthresholdishas been exceeded. MODE 3,PIN 5 GROUNDED With pin5 grounded,theinputarmingthresholdissetto0V, ±25mV maximum. Positive-goingzerocrossings arm thechip,and thenextnegative-goingzerocrossingtriggersit.Thisistheverybasicform ofzero-crossing detection. ONE SHOT TIMING The one shottimingissetby a resistorand capacitorconnectedtopin14.The recommended maximum resistor valueis150kohms. The capacitorvaluecan be changed as needed, as longas the capacitortypedoes not presentany signfigantleakagethatwouldadverselyaffecttheRC timeconstant. The outputpulsewidthis: pulsewidth= 0.673x R x C (1) Fora givenOne Shotpulsewidth,therecommended maximum inputsignalfrequencyis: Fin(max)= 1/(1.346x R x C) (2) In the applicationexample shown inFigure17 (R=150kohms, C=0.001µF) the recommended maximum input frequencywilltypicallybe 5kHz.Operatingwithinputfrequenciesabove therecommended Fin(max)valuemay resultinunreliableperformanceoftheOne Shot circuitry.For thoseapplicationswhere theOne Shot circuitis notrequired,devicepin14 can be tieddirectlytoGround. LOGIC INPUTS Insome systemsitisnecessarytoexternallygeneratepulses,such as duringstallconditionswhen thevariable reluctancesensorhas no output.Externalpulseinputsatpin9 are gatedthroughtopin10 when InputSelect (pin11)ispulledhigh.Pin12 isa directoutputfortheone shotand isunaffectedby thestatusofpin11. Input/outputpins9, 11, 10, and 12 are allCMOS logiccompatible.In addition,pins9, 11, and 12 are TTL compatible.Pin10 isnotensuredtodrivea TTL load. Pins1,4,6 and 13 have no internalconnectionsand can be grounded. Copyright© 2000–2013,Texas InstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LM1815
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REVISION HISTORY
Changes from RevisionE (March 2013)toRevisionF Page
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www.ti.com 19-Mar-2015 Addendum-Page 1 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/Ball Finish (6) MSL Peak Temp (3) Op Temp (°C) Device Marking (4/5) Samples LM1815M NRND SOIC D 14 55 TBD Call TI Call TI -40 to 125 LM1815M LM1815M/NOPB ACTIVE SOIC D 14 55 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM1815M LM1815MX/NOPB ACTIVE SOIC D 14 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM1815M LM1815N/NOPB ACTIVE PDIP NFF 14 25 Green (RoHS & no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM1815N (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width.
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*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 PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 Pack Materials-Page 1
*All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM1815MX/NOPB SOIC D 14 2500 367.0 367.0 35.0 PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 Pack Materials-Page 2
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