{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LD1117AS25TR","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"LD1117AS25TR","canonicalUrl":"https://icboms.com/stmicroelectronics/LD1117AS25TR","factsUrl":"https://icboms.com/api/mcp/products/LD1117AS25TR","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics LD1117AS25TR, fixed 2.5 V output LDO, 1 A, 80 dB PSRR at 120 Hz, dropout 1.3 V max, SOT-223 package, 0°C to 125°C.","salesMarkdown":"## Fixed 2.5 V rail — what the 1 A rating and dropout mean for the BOM The LD1117AS25TR is a fixed 2.5 V output, positive-voltage LDO regulator from STMicroelectronics, rated for 1 A continuous output current. The 1.3 V maximum dropout at full load means the input rail must stay above 3.8 V to maintain regulation — budget that headroom when the upstream supply is a 5 V bus or a 3.6 V battery that sags under load. ## 80 dB PSRR — where the ripple rejection matters With 80 dB of power-supply rejection at 120 Hz, this part attenuates rectified mains ripple by a factor of 10,000. That makes it a good fit for cleaning up a post-rectifier rail feeding a sensitive analog front-end, an audio codec supply, or a low-noise sensor bias. The 10 mA quiescent current is typical for a 1 A LDO of this generation — not a low-Iq part for battery-idle designs, but acceptable where the load current dominates the power budget. ## SOT-223 package — reflow and footprint reality The part ships in a SOT-223 (TO-261-4) surface-mount package. For 1 A continuous at 1.3 V dropout, expect about 1.3 W dissipation; a 1-square-inch copper pour on the top layer is the minimum to keep the junction below 125°C at 25°C ambient. STMicroelectronics lists the LD1117AS25TR as obsolete. No last-time-buy window remains; the part is sourced as available inventory.","metaTitle":"ST LD1117AS25TR LDO Regulator, Fixed 2.5V, 1A, SOT-223","metaDescription":"STMicroelectronics LD1117AS25TR: fixed 2.5 V output, 1 A LDO, 80 dB PSRR at 120 Hz, dropout 1.3 V max. SOT-223 package.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"STMicroelectronics","PSRR":"80dB (120Hz)","Series":"-","Package":"Tape & Reel (TR)","Output Type":"Fixed","Mounting Type":"Surface Mount","Package / Case":"TO-261-4, TO-261AA","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Control Features":"-","Current - Output":"1A","Base Product Number":"LD1117","Protection Features":"Over Current, Over Temperature","Number of Regulators":"1","Output Configuration":"Positive","Operating Temperature":"0°C ~ 125°C","Voltage - Input (Max)":"15V","Voltage Dropout (Max)":"1.3V @ 1A","Voltage - Output (Max)":"-","Supplier Device Package":"SOT-223","Current - Quiescent (Iq)":"10 mA","Voltage - Output (Min/Fixed)":"2.5V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$3.7700","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/1f53874c71a4fc18a5ab2ae913a72296.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LD1117AS25TR/alternatives.json"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/LD1117AS25TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/LD1117AS25TR 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}}