{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451.630NRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451.630NRL","canonicalUrl":"https://icboms.com/littelfuse-inc/0451.630NRL","factsUrl":"https://icboms.com/api/mcp/products/0451.630NRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, surface-mount fast-blow fuse, 630 mA, 125 VAC/125 VDC, 50 A breaking capacity, 2-SMD square end block package, Tape & Reel.","salesMarkdown":"The Littelfuse 0451.630NRL is a 630 mA fast-blow fuse in the NANO²® 451 series, rated for 125 VAC and 125 VDC with a 50 A interrupting capacity at rated voltage. That 50 A breaking capacity means it safely clears a fault up to that current without rupturing the package — critical for secondary-side protection in a power supply where the available fault current can hit that level. Fast-blow response means it opens quickly on a short circuit but tolerates brief inrush pulses below the melting I²t of 0.143 — a typical fit for protecting control circuits, indicator lamps, or small DC motors where the start-up surge is short and the fault current needs to be cleared fast. ## Package and board-fit — what the 2-SMD square end block demands The 2-SMD square end block package, 6.10 mm long by 2.69 mm wide and tall, is a standard subminiature footprint for pick-and-place assembly. The 0.305 ohm cold resistance at 630 mA means a voltage drop of about 0.19 V at rated current — negligible for a 125 V rail but worth checking on a 5 V supply where every millivolt counts. Surface-mount mounting and Tape & Reel packaging mean it flows through standard reflow profiles.","metaTitle":"0451.630NRL Littelfuse NANO² 451 Fuse, 630 mA, 125 V","metaDescription":"0451.630NRL Littelfuse NANO² 451 surface-mount fast-blow fuse, 630 mA, 125 VAC/DC, 50 A breaking capacity. Active production. CSA, UL approved. Quoted 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":"0.143","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","Approval Agency":"CSA, 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":"0.305 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"630 mA","Operating Temperature":"-55°C~125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.6002","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the breaking capacity of 0451.630NRL?","answer":"The breaking capacity is 50 A at the rated voltage of 125 VAC or 125 VDC. This means the fuse can safely interrupt a fault current up to 50 A without rupturing the package."},{"question":"What approvals does 0451.630NRL carry?","answer":"The fuse is approved by CSA and UL, which covers North American regulatory acceptance for most equipment-level circuit protection applications."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451.630NRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451.630NRL 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}}