{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM317D2T","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"LM317D2T","canonicalUrl":"https://icboms.com/stmicroelectronics/LM317D2T","factsUrl":"https://icboms.com/api/mcp/products/LM317D2T","rawCanonicalId":null},"summary":{"shortDescription":"ON Semiconductor LM317D2T, positive adjustable voltage regulator, 1.5 A output, 40 V max input, 1.2 V to 37 V output range, PSRR 80 dB ~ 65 dB at 120 Hz, D²Pak (TO-263) surface-mount package, 0 °C to 125 °C operating temperature.","salesMarkdown":"## 1.5 A adjustable regulator in D²Pak — what the ratings mean The LM317D2T is a positive adjustable voltage regulator from the LM317 family, delivering up to 1.5 A output current from a 1.2 V to 37 V adjustable range. It accepts an input voltage up to 40 V and provides line and load regulation typical of the three-terminal adjustable regulator topology. ## 40 V input ceiling and 1.5 A load — where the headroom lives The 40 V maximum input voltage sets the upper rail the part can survive — design the input bus below that with margin for transients. The 1.5 A output rating is continuous; the actual current the part can deliver at a given output voltage depends on the input-output differential and the thermal dissipation in the D²Pak. The 10 mA quiescent current is drawn regardless of load, so at light loads the efficiency drops — this matters for always-on or battery-backed rails. PSRR is specified at 80 dB to 65 dB at 120 Hz, which is the full-wave rectified line frequency and its second harmonic. For a 50 Hz mains, the 100 Hz ripple rejection sits in that band — the 80 dB floor at light load gives about 10,000:1 attenuation of input ripple, dropping to around 1,800:1 as the load pulls the output down. That is adequate for most analog supply rails but not for precision references without post-filtering. ## Protection features and operating range Built-in protection includes over-current limiting, over-temperature shutdown, and short-circuit current limiting — standard for the LM317 family. The single regulator output is configured as positive adjustable, with the adjustment pin setting the output via an external resistor divider.","metaTitle":"LM317D2T adjustable voltage regulator, 1.5 A, D²Pak","metaDescription":"LM317D2T positive adjustable voltage regulator, 1.5 A output, 40 V input max, PSRR 80 dB at 120 Hz, D²Pak surface-mount package.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"STMicroelectronics","PSRR":"80dB ~ 65dB (120Hz)","Series":"-","Package":"Tube","Output Type":"Adjustable","Mounting Type":"Surface Mount","Package / Case":"TO-263-3, D²Pak (2 Leads + Tab), TO-263AB","Product Status":"Obsolete","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":"D²PAK","Current - Quiescent (Iq)":"10 mA","Voltage - Output (Min/Fixed)":"1.2V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9200","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/e8f6730a7d458d8832c68f87c604e646.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM317D2T/alternatives.json"},"ai":{"faq":[{"question":"What is the equivalent or replacement for LM317D2T?","answer":"The LM317 family includes many pin-compatible through-hole and surface-mount variants — the LM317T in TO-220 and the LM317D2TR4G in D²Pak are common alternatives, but the exact pinout, package footprint, and thermal characteristics must be verified against the BOM position before substituting."},{"question":"What is the difference between LM317D2T and LM317T?","answer":"The primary difference is the package: the LM317D2T is in a D²Pak (TO-263) surface-mount package with an exposed tab, while the LM317T is in a TO-220 through-hole package. The electrical specifications — 1.5 A output, 40 V input max, adjustable output from 1.2 V to 37 V — are the same across the LM317 family. The package choice drives the thermal design and the assembly process: D²Pak suits reflow soldering, TO-220 suits through-hole or heatsink mounting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/LM317D2T","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/LM317D2T when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T18:03:28.771Z","lastPublished":"2026-07-22T18:03:28.771Z","indexable":true}}