{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"04511.25NRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"04511.25NRL","canonicalUrl":"https://icboms.com/littelfuse-inc/04511.25NRL","factsUrl":"https://icboms.com/api/mcp/products/04511.25NRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 series, Board Mount Surface Mount Fuse, Fast Blow, 1.25 A, 125 V AC/DC, 50 A breaking capacity, 2-SMD square end block package, Tape & Reel.","salesMarkdown":"The 04511.25NRL comes in a 2-SMD square end block package measuring 0.240\" x 0.106\" x 0.106\" (6.10 mm x 2.69 mm x 2.69 mm). Surface-mount footprint means the fuse sits flush on the board — no through-hole leads to route, but the pad geometry must match the end-block terminations for reliable solder wetting and to keep the DC cold resistance at the listed 0.078 Ohms. This is a Tape & Reel (TR) delivery format, so it feeds directly into a pick-and-place line. The NANO² 451 series is the identity here — a compact SMD fuse family designed for dense PCB layouts where a cartridge-style fuse won't fit. ## What the ratings mean for your BOM Rated 1.25 A continuous with a fast-blow response — this fuse opens quickly on overcurrents above the threshold, protecting downstream components from short-circuit energy. The 125 V AC and 125 V DC rating is the same on both sides, so it works in single-supply DC rails or AC line-side circuits up to that voltage. Breaking capacity is 50 A at the rated voltage. That means it can safely interrupt a fault current up to 50 A without rupturing or arcing across the package — critical for clearing hard shorts on a 125 V rail where the available fault current from a bulk capacitor bank or power supply could exceed the fuse's interrupt rating. Melting I²t is 0.664 — this is the energy needed to melt the fuse element. Use it to coordinate with downstream semiconductors: the I²t of the fuse should be below the I²t withstand of the protected device (like a diode or FET) to ensure the fuse clears before the component fails short. ## Compliance and approvals Approved by CSA, PSE, and UL — these are the primary safety certifications for North American and Japanese markets. UL recognition means the fuse is tested to UL 248-14 for supplemental overcurrent protection; CSA and PSE cover Canadian and Japanese electrical safety standards respectively.","metaTitle":"Littelfuse 04511.25NRL NANO² 451 SMD Fuse, 1.25 A, 125 V","metaDescription":"Littelfuse 04511.25NRL NANO² 451 surface-mount fast-blow fuse, 1.25 A at 125 V AC/DC, 50 A breaking capacity. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Color":"-","Series":"NANO²® 451","Package":"Tape & Reel (TR)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"0.664","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","Approval Agency":"CSA, PSE, UL","lifecycle_stage":"unknown","Size / Dimension":"0.240\\\" L x 0.106\\\" W x 0.106\\\" H (6.10mm x 2.69mm x 2.69mm)","DC Cold Resistance":"0.078 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"1.25 A","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.5926","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/2e33e7b2503f3f5110226be89402b64a.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Where can I buy 04511.25NRL and how do I get a price?","answer":"The 04511.25NRL is an active-production part sourced through independent distribution."},{"question":"What compliance documentation does Littelfuse provide for 04511.25NRL?","answer":"The fuse carries CSA, PSE, and UL approvals. These certifications cover North American (UL 248-14), Canadian (CSA), and Japanese (PSE) safety standards for supplemental overcurrent protection."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/04511.25NRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/04511.25NRL 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}}