{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045102.5NRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045102.5NRL","canonicalUrl":"https://icboms.com/littelfuse-inc/045102.5NRL","factsUrl":"https://icboms.com/api/mcp/products/045102.5NRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 Series, Board Mount Surface Mount Fuse, 045102.5NRL, 2.5 A, 125 V AC/DC, Fast Blow, 2-SMD Square End Block.","salesMarkdown":"## 2.5 A fast-blow in a small SMD package The 045102.5NRL is a 2.5 A fast-blow surface-mount fuse from the Littelfuse NANO²® 451 series, rated for 125 V AC and DC with a breaking capacity of 50 A at rated voltage. That 50 A interrupt rating means it can safely clear a short-circuit fault up to that level without rupturing the package — critical for secondary-side protection in power supplies and DC bus circuits where the available fault current stays under 50 A. ## What the ratings mean for your BOM The 2.5 A current rating and fast-blow response time mean this fuse opens quickly on overcurrent but will not tolerate sustained inrush — a capacitive input or motor start that draws 4 A for 10 ms may blow it. Melting I²t is 1.029 — this is the energy to open the element. For a downstream semiconductor (diode, MOSFET) that must survive a fault until the fuse clears, the I²t of the fuse should be lower than the device's surge rating. The 1.029 figure is moderate; pair it with a semiconductor rated for at least 2 A²s surge. Housed in a 2-SMD square end block case measuring 6.10 mm x 2.69 mm x 2.69 mm — the same footprint as the standard NANO² 451 series. The square end terminations reflow reliably with a standard solder profile; the part is symmetric, so orientation does not matter during pick-and-place.","metaTitle":"Littelfuse 045102.5NRL NANO² 451 Fuse, 2.5 A, 125 V","metaDescription":"Littelfuse 045102.5NRL NANO²® 451 surface-mount fuse, 2.5 A, 125 V AC/DC, 50 A breaking capacity, fast blow. 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) Cut Tape (CT)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"1.029","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":"0.0286 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"2.5 A","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4600","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/2af44192316ab81fbaa6428998cbb6d9.pdf","sourceUrl":null},"ai":{"faq":[{"question":"How do I get current pricing and availability for 045102.5NRL?","answer":"Submit an RFQ for the 045102.5NRL. Pricing and stock are confirmed at quote time against your target quantity and delivery window. The part is sourced to order through our distribution network."},{"question":"What approvals does the 045102.5NRL carry?","answer":"The fuse is approved by CSA, PSE, and UL. The UL listing covers North American equipment safety; PSE is required for Japan market compliance."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045102.5NRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045102.5NRL 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}}