{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451007.MRSN","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451007.MRSN","canonicalUrl":"https://icboms.com/littelfuse-inc/0451007.MRSN","factsUrl":"https://icboms.com/api/mcp/products/0451007.MRSN","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, 0451007.MRSN, 7 A, 125 VAC, 50 A breaking capacity, fast blow, surface mount, 2-SMD square end block.","salesMarkdown":"## 7 A fast blow SMD fuse — NANO² 451 series The 0451007.MRSN is a 7 A, 125 VAC rated fast-blow fuse from Littelfuse's NANO² 451 series, housed in a 2-SMD square end block package for surface-mount assembly. Breaking capacity is 50 A at rated voltage — sufficient for clearing low-to-moderate fault currents in secondary-side protection of power supplies, lighting ballasts, and industrial control boards. ## Inrush handling and cold resistance Melting I²t is 10.32 A²s — this sets the energy threshold the fuse absorbs before opening; a downstream capacitor bank charging at turn-on must stay below this integral to avoid nuisance blowing. DC cold resistance is 0.009 Ω, so at 7 A the I²R loss is under 0.5 W — negligible thermal contribution in still air on a standard FR-4 board. ## Approvals and temperature range Approved by CSA, METI, and UR — the fuse carries the marks needed for equipment sold into North American and Japanese markets.","metaTitle":"0451007.MRSN Littelfuse NANO² 451","metaDescription":"0451007.MRSN Littelfuse NANO² 451 series, 7 A, 125 VAC, 50 A breaking capacity, fast blow, surface mount. Active production. Request a quote.","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":"10.32","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","Approval Agency":"CSA, METI, UR","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":"0.009 Ohms","Voltage Rating - AC":"125 V","Current Rating (Amps)":"7 A","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4900","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"How do I get current pricing and availability for 0451007.MRSN?","answer":"Submit an RFQ for the 0451007.MRSN."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451007.MRSN","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451007.MRSN 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}}