{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM317KCSE3","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM317KCSE3","canonicalUrl":"https://icboms.com/texas-instruments/LM317KCSE3","factsUrl":"https://icboms.com/api/mcp/products/LM317KCSE3","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments LM317KCSE3, adjustable positive linear voltage regulator, 1.5A output, 40V input max, 37V output max, TO-220-3 package, through-hole mount, 0°C to 125°C.","salesMarkdown":"## Adjustable regulator for the 1.5A rail The Texas Instruments LM317KCSE3 is the through-hole TO-220-3 variant of the classic adjustable positive voltage regulator. It delivers up to 1.5A output current with an output adjustable from 1.25V up to 37V, fed from an input rail rated to 40V max. At 1.5A continuous output, this regulator covers medium-current loads: analog front-end supplies, fan drivers, relay coils, or post-switcher clean rails. Built-in over-current, over-temperature, and short-circuit protection means you can skip external foldback or crowbar circuits for basic fault handling, though a reverse-bias diode across the output is still good practice if the load can back-drive the regulator. ## PSRR at 120 Hz — line-frequency ripple rejection Ripple rejection runs 80 dB to 65 dB at 120 Hz, which is the standard rectified-mains frequency. That 80 dB floor at lighter loads means the output sees only microvolts of ripple from a poorly filtered bulk cap — relevant if you are feeding a sensitive analog chain (op-amp rails, ADC reference, audio preamp). At higher loads the rejection drops to 65 dB, still adequate for most mixed-signal boards. If you need better rejection above a few kHz, plan for a post-filter LC stage. ## Package and mounting — TO-220-3 through-hole The tab is electrically connected to the output pin, so an insulating pad and washer are needed if you mount it to a grounded chassis. Through-hole mounting suits point-of-load regulation on boards where wave solder is the primary assembly process, or where the thermal mass of the tab needs a bolt-down heat sink rather than PCB copper. That covers commercial and most industrial environments — office equipment, appliance control boards, industrial sensor interfaces, power supplies for test gear — but not automotive under-hood or outdoor telecom cabinets where -40°C cold starts are required. If the bill of materials needs a -40°C low end, you would step to the LM317M or an automotive-grade variant. No last-time-buy risk, no PCN for imminent EOL. The classic LM317 footprint means second-source options exist across multiple vendors, though the KCSE3 suffix is a specific TI orderable.","metaTitle":"LM317KCSE3 Adjustable Positive Regulator, 1.5A, TO-220-3","metaDescription":"LM317KCSE3 adjustable positive voltage regulator from Texas Instruments. 1.5A output, 40V input max, 37V output max, TO-220-3. Active lifecycle, ROHS3.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"Texas Instruments","PSRR":"80dB ~ 65dB (120Hz)","Series":"-","Package":"Tube","Output Type":"Adjustable","Mounting Type":"Through Hole","Package / Case":"TO-220-3","Product Status":"Active","lifecycle_stage":"eol_hot","Control Features":"-","Current - Output":"1.5A","Base Product Number":"LM317","Protection Features":"Over Current, Over Temperature, Short Circuit","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"0°C~125°C","Voltage - Input (Max)":"40V","Voltage Dropout (Max)":"-","Voltage - Output (Max)":"37V","Supplier Device Package":"TO-220-3","Current - Quiescent (Iq)":"10 mA","Voltage - Output (Min/Fixed)":"1.25V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9000","priceTiers":[{"qty":1,"price":"$0.90000","currency":"USD"},{"qty":10,"price":"$0.79100","currency":"USD"},{"qty":25,"price":"$0.74280","currency":"USD"},{"qty":100,"price":"$0.60610","currency":"USD"},{"qty":250,"price":"$0.56296","currency":"USD"},{"qty":500,"price":"$0.47912","currency":"USD"},{"qty":1000,"price":"$0.38330","currency":"USD"},{"qty":2500,"price":"$0.34736","currency":"USD"},{"qty":5000,"price":"$0.33900","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/6e4aef63b3328a11f0a16987811b26d6.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM317KCSE3/alternatives.json"},"ai":{"faq":[{"question":"What is the output current of LM317KCSE3?","answer":"The LM317KCSE3 is rated for 1.5A output current."},{"question":"How does LM317KCSE3 compare to LM317T?","answer":"The LM317KCSE3 and LM317T are both adjustable positive regulators in a TO-220-3 package with the same 1.5A output rating. The difference is in the ordering code suffix — the KCSE3 is a specific TI orderable that may carry different packing or test-level options. Electrically they are pin-compatible and interchangeable in the same footprint."},{"question":"What is LM317KCSE3's PSRR?","answer":"The PSRR is 80 dB to 65 dB at 120 Hz."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM317KCSE3","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM317KCSE3 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}