[{"data":1,"prerenderedAt":226},["ShallowReactive",2],{"component:lm317:en":3},{"component":4,"localizationFallbackIssues":163,"related":164,"equivalentSlugs":225},{"schemaVersion":5,"governance":6,"id":18,"mpn":19,"slug":18,"primaryCategory":20,"manufacturers":21,"lifecycleStatus":23,"shortDescription":24,"deepTechnicalOverview":25,"packages":26,"absoluteMaximums":49,"parametricAttributes":52,"gotchas":122,"datasheetUrl":17,"documentationSources":137,"applicationCircuits":146,"equivalents":151,"mountedOnBoards":152,"seo":153},"1.0.0",{"publication":7,"verification":10,"provenance":15},{"status":8,"publishedDate":9},"published","2026-10-13",{"status":11,"verifiedDate":9,"verifiedBy":12,"checklist":13},"verified","Codex (independent manufacturer documentary\u002Ftechnical\u002Fpackage and full-five-locale LLM semantic review; owner publication GO; no bench or native-human claim)",{"schema":14,"technicalFacts":14,"relationships":14,"sources":14},true,{"sourceUrls":16},[17],"https:\u002F\u002Fwww.st.com\u002Fresource\u002Fen\u002Fdatasheet\u002Flm217.pdf","lm317","LM317T","voltage_regulator",[22],"STMicroelectronics","active","Adjustable 1.2V to 37V positive linear voltage regulator capable of supplying in excess of 1.5A in a TO-220 package with ADJ-OUT-IN pinout and internal thermal protection.","The LM317T is an adjustable 3-terminal positive linear voltage regulator manufactured by STMicroelectronics (Document DS0433, Rev 22, December 2021). Housed in the through-hole TO-220 package with an ADJ-OUT-IN pinout (Pin 1 ADJ, Pin 2 OUT, Pin 3 IN, with the metallic tab internally connected to OUT), it supplies in excess of 1.5A when VI - VO \u003C= 15V and internal dissipation is within rated limits, with a maximum input-to-output differential of 40V. Operating characteristics under Table 4 include a nominal reference voltage VREF of 1.25V (1.20V to 1.30V), typical line regulation of 0.01%\u002FV, typical load regulation of 5.0mV (for VO \u003C= 5V), typical adjustment pin current of 50 µA, and minimum load current requirement up to 10mA at 40V differential. The regulator integrates internal current limiting, thermal overload protection, and safe-operating-area (SOA) protection.",[27],{"packageType":28,"pinCount":29,"thermalResistanceThetaJA":30,"thermalResistanceThetaJC":31,"pins":32},"TO-220",3,50,5,[33,40,45],{"pinNumber":34,"pinName":35,"electricalType":36,"isFiveVoltTolerant":37,"internalPull":38,"description":39},1,"ADJ","passive",false,"none","Output adjustment terminal (maintains 1.25V nominal reference between OUT and ADJ; adjustment pin current ~50 µA typical)",{"pinNumber":41,"pinName":42,"electricalType":43,"isFiveVoltTolerant":37,"internalPull":38,"description":44},2,"OUT","power_out","Regulated output voltage terminal (internally connected to the TO-220 metallic mounting tab)",{"pinNumber":29,"pinName":46,"electricalType":47,"isFiveVoltTolerant":37,"internalPull":38,"description":48},"IN","power_in","Unregulated DC input voltage terminal (input-to-output differential VI - VO rated up to 40V max)",{"storageTempMinC":50,"storageTempMaxC":51},-65,150,[53,61,68,75,82,87,94,101,107,114],{"symbol":54,"name":55,"typicalValue":56,"minValue":57,"maxValue":58,"unit":59,"testCondition":60},"VREF","Reference Voltage","1.25",1.2,1.3,"V","VI - VO = 2.5 V to 40 V, IO = 10 mA to 1.5 A, PD \u003C= 20 W, TJ = 0°C to 125°C",{"symbol":62,"name":63,"typicalValue":64,"maxValue":65,"unit":66,"testCondition":67},"Line_reg","Line Regulation","0.01",0.04,"%\u002FV","VI - VO = 3 V to 40 V, IO = 500 mA, TJ = 25°C",{"symbol":69,"name":70,"typicalValue":71,"maxValue":72,"unit":73,"testCondition":74},"Load_reg","Load Regulation","5.0",25,"mV","VI - VO = 5 V, VO \u003C= 5 V, IO = 10 mA to 1.5 A, TJ = 25°C",{"symbol":76,"name":77,"typicalValue":78,"maxValue":79,"unit":80,"testCondition":81},"IADJ","Adjustment Pin Current","50",100,"µA","VI - VO = 5 V, IO = 500 mA, TJ = 0°C to 125°C",{"symbol":83,"name":84,"typicalValue":85,"maxValue":31,"unit":80,"testCondition":86},"delta_IADJ","Adjustment Pin Current Change","0.2","VI - VO = 2.5 V to 40 V, IO = 10 mA to 1.5 A, TJ = 0°C to 125°C",{"symbol":88,"name":89,"typicalValue":90,"maxValue":91,"unit":92,"testCondition":93},"IO_min","Minimum Load Current","3.5",10,"mA","VI - VO = 40 V, TJ = 0°C to 125°C",{"symbol":95,"name":96,"typicalValue":97,"minValue":98,"unit":99,"testCondition":100},"IO_max","Maximum Output Current","2.2",1.5,"A","VI - VO \u003C= 15 V, PD \u003C 20 W, TJ = 0°C to 125°C",{"symbol":102,"name":103,"typicalValue":104,"unit":105,"testCondition":106},"eN","Output Noise Voltage","0.003","%","VI - VO = 5 V, IO = 500 mA, B = 10 Hz to 100 kHz, TJ = 25°C (percentage of VO)",{"symbol":108,"name":109,"typicalValue":110,"minValue":111,"unit":112,"testCondition":113},"SVR","Supply Voltage Rejection","80",66,"dB","VI - VO = 5 V, IO = 500 mA, CADJ = 10 µF between ADJ and GND, f = 120 Hz, TJ = 25°C",{"symbol":115,"name":116,"typicalValue":117,"minValue":118,"maxValue":119,"unit":120,"testCondition":121},"TJ","Operating Junction Temperature (Absolute Maximum)","—",0,125,"°C","LM317, Table 1 absolute maximum junction-temperature range; not an ambient-temperature rating",[123,128,132],{"title":124,"severity":125,"description":126,"mitigationStrategy":127},"Mounting Tab Electrically Connected to VOUT, NOT Ground","critical","The TO-220 metallic mounting tab is internally connected to Pin 2 (OUT). Mounting the regulator directly to a grounded metal chassis or shared heatsink ties the regulated output to ground or interconnects outputs of multiple regulators on the same heatsink. If grounded, the regulated output collapses and internal protection limits current according to thermal and voltage conditions.","When mounting to a grounded heatsink or shared metallic surface, electrically isolate the mounting tab using an electrically insulating and thermally conductive pad together with an insulating shoulder washer on the mounting screw. Verify electrical isolation with an ohmmeter before applying power.",{"title":129,"severity":125,"description":130,"mitigationStrategy":131},"Minimum Load Current Requirement (10mA Maximum at 40V Differential)","The internal bias current of the LM317 returns to circuit common through the OUT pin, requiring a minimum load current of 3.5mA typical and up to 10mA (at VI - VO = 40V over operating temperature) to maintain proper regulation. If total output load current is insufficient, the output voltage can rise toward the unregulated input rail.","Size the output voltage divider so that programming resistor R1 (between OUT and ADJ) draws the required minimum load current: check VREF(min) \u002F R1(max) >= 10 mA using the applicable reference-voltage conditions and worst-case resistor tolerance, including temperature. A nominal 120 Ω resistor draws 1.25 V \u002F 120 Ω = 10.4 mA nominally; at VREF = 1.20 V and the +1% resistance extreme (R1 = 121.2 Ω), the calculated current is approximately 9.90 mA. Verify minimum-load requirements for the operating envelope.",{"title":133,"severity":134,"description":135,"mitigationStrategy":136},"Discharge Protection Diodes for Capacitive Loads (CADJ and COUT)","warning","When using an adjustment pin bypass capacitor CADJ (recommended for improving ripple rejection up to 80dB typical) or an output filter capacitor COUT, sudden loss or shorting of the input supply or output rail can cause capacitors to discharge back into internal regulator nodes. Specifically, an input short discharges COUT back through the regulator toward IN, while an output short discharges CADJ into the ADJ terminal.","ST DS0433 Section 6 describes external protection diodes as good practice with bypass or output capacitors: D1 has anode at OUT and cathode at IN to bypass COUT discharge around the regulator; D2 has anode at ADJ and cathode at OUT to discharge CADJ into the output rail. Select diode voltage, discharge-current and energy ratings for the actual capacitances, voltages and fault conditions.",[138],{"title":139,"url":17,"type":140,"authority":141,"publisher":22,"documentNumber":142,"revision":143,"releaseDate":144,"language":145},"LM217, LM317: 1.2 V to 37 V adjustable voltage regulators","datasheet","primary","DS0433","Rev 22","2021-12","EN",[147],{"title":148,"schematicSlug":149,"topology":150},"LM317 Constant Current Source","lm317-constant-current-source","ST LM317T current regulator with a series sense resistor between OUT and IOUT.",[],[],{"canonicalUrl":154,"metaTitle":155,"metaDescription":156,"primarySearchCluster":157,"structuredDataSchema":162},"https:\u002F\u002Fcircuitbase.tech\u002Fcomponent\u002Flm317","LM317T Adjustable Voltage Regulator Pinout & Datasheet | CircuitBase","Complete STMicroelectronics LM317T adjustable linear regulator specifications, TO-220 pinout (ADJ-OUT-IN), 1.25V VREF, 1.5A load envelope, and thermal tab gotchas.",[158,159,160,161],"lm317 pinout","lm317t datasheet","lm317 to-220","lm317 voltage regulator","Product",null,[165,179,196,212],{"id":166,"slug":166,"mpn":167,"primaryCategory":20,"manufacturers":168,"shortDescription":171,"packages":172,"packageTypes":176,"voltage":177},"lm7805","LM7805",[169,22,170],"Texas Instruments","onsemi","5 V, 1.5 A fixed positive linear voltage regulator with internal current limiting and thermal shutdown, in TO-220 and D2PAK packages.",[173,174],{"packageType":28,"pinCount":29},{"packageType":175,"pinCount":29},"D2PAK",[28,175],{"context":178,"min":-1,"max":-1,"typical":-1,"outputTypical":31},"input",{"id":180,"slug":180,"mpn":181,"primaryCategory":20,"manufacturers":182,"shortDescription":185,"packages":186,"packageTypes":190,"voltage":191,"recommendedOperating":195},"ams1117-3-3","AMS1117-3.3",[183,184],"Advanced Monolithic Systems","Various","1A low-dropout positive linear voltage regulator with fixed 3.3V output in SOT-223 package.",[187],{"packageType":188,"pinCount":189},"SOT-223",4,[188],{"context":178,"min":192,"max":193,"typical":31,"outputTypical":194},4.75,15,3.3,{"supplyVoltageMinV":192,"supplyVoltageTypV":31,"supplyVoltageMaxV":193},{"id":197,"slug":197,"mpn":198,"primaryCategory":20,"manufacturers":199,"shortDescription":200,"packages":201,"packageTypes":206,"voltage":207,"recommendedOperating":211},"lm2596","LM2596",[169],"Step-down switching voltage regulator capable of driving a 3A load with 150 kHz fixed frequency, 40V input range, internal thermal shutdown, and cycle-by-cycle current limiting in TO-220 and TO-263 packages.",[202,204],{"packageType":203,"pinCount":31},"TO-220-5",{"packageType":205,"pinCount":31},"TO-263-5",[203,205],{"context":178,"min":208,"max":209,"typical":210},4.5,40,12,{"supplyVoltageMinV":208,"supplyVoltageTypV":210,"supplyVoltageMaxV":209},{"id":213,"slug":213,"mpn":214,"primaryCategory":20,"manufacturers":215,"shortDescription":216,"packages":217,"packageTypes":220,"voltage":221,"recommendedOperating":224},"tl431","TL431LP",[169],"Adjustable precision shunt regulator with programmable output voltage from 2.495V to 36V, 1mA to 100mA cathode current capability, and 0.2Ω typical dynamic impedance in a 3-pin TO-92 package.",[218],{"packageType":219,"pinCount":29},"TO-92",[219],{"context":178,"min":222,"max":223,"typical":222},2.495,36,{"supplyVoltageMinV":222,"supplyVoltageTypV":222,"supplyVoltageMaxV":223},{},1793836424156]