{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045103.5MRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045103.5MRL","canonicalUrl":"https://icboms.com/littelfuse-inc/045103.5MRL","factsUrl":"https://icboms.com/api/mcp/products/045103.5MRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 Series, Board Mount Surface Mount Fuse, 045103.5MRL, 3.5 A, 125 V AC/DC, Fast Blow, 2-SMD Square End Block Package.","salesMarkdown":"## Active production, 3.5 A fast-blow in a 2-SMD square-end block The Littelfuse 045103.5MRL is an active-production NANO² 451 series surface-mount fuse rated 3.5 A at 125 V AC and 125 V DC, with a fast-blow response time. It comes in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, making it a drop-in fit for high-density board layouts where space is tight. Breaking capacity is 50 A at the rated voltage — this fuse safely interrupts a fault current up to 50 A without rupturing or arcing, which is adequate for most secondary-side DC rails and low-power AC circuits. Melting I²t is 2.469 A²s, a measure of the energy needed to open the fuse element; a lower I²t means faster clearing under surge conditions, reducing stress on downstream components. ## Approvals and temperature range The fuse carries CSA, PSE, and UL approvals, meaning it is accepted in North American and Japanese regulatory jurisdictions without additional component-level testing.","metaTitle":"Littelfuse 045103.5MRL NANO² 451 Fuse, 3.5 A, 125 V","metaDescription":"Littelfuse 045103.5MRL NANO² 451 surface-mount fuse, 3.5 A, 125 V AC/DC, fast blow, 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) Cut Tape (CT)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"2.469","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":"0.02 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"3.5 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/2e33e7b2503f3f5110226be89402b64a.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What compliance documentation does Littelfuse provide for 045103.5MRL?","answer":"The fuse holds CSA, PSE, and UL agency approvals, which cover safety and performance compliance for North American and Japanese markets."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045103.5MRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045103.5MRL 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}}