{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045106.3MRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045106.3MRL","canonicalUrl":"https://icboms.com/littelfuse-inc/045106.3MRL","factsUrl":"https://icboms.com/api/mcp/products/045106.3MRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 Series, Board Mount Surface Mount Fuse, 045106.3MRL, 6.3 A, 125 V AC/DC, Fast Blow, 50 A Breaking Capacity, 2-SMD Square End Block Package.","salesMarkdown":"## What the 6.3 A rating means for your board The 045106.3MRL is a Littelfuse NANO²® 451 series surface-mount fuse rated 6.3 A continuous at 125 V AC or DC. The fast-blow response time means it clears on moderate overcurrents quickly — the element fuses before downstream traces or semiconductors reach their I²t limit. For a 6.3 A rail, the 0.0096 ohm DC cold resistance keeps voltage drop under 60 mV at full load, which matters for low-voltage supplies where every millivolt of headroom counts. ## Breaking capacity and fault clearing Rated breaking capacity is 50 A at the rated voltage. In a 125 V circuit, this fuse safely interrupts a fault current up to 50 A without rupturing the package or sustaining an arc. The melting I²t of 9.17 A²s is the energy needed to open the element — coordinate this with the I²t rating of the downstream components (traces, connectors, semiconductors) so the fuse clears before they fail. ## Approvals and temperature envelope At the high end, derate the continuous current per the manufacturer's curve (not reproduced here) to avoid nuisance opening from ambient heating. Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm. Surface-mount assembly with tape-and-reel packaging (Cut Tape option also available) — the square end terminals provide good solder joint visibility for AOI. The compact footprint suits dense PCB layouts where a through-hole cartridge fuse would consume too much real estate. ## Sourcing and lifecycle posture Listed as Active in the manufacturer's lifecycle record. No end-of-life notice or successor part is on file. The NANO² 451 series is a mature, widely stocked line; no single-source risk flagged.","metaTitle":"045106.3MRL Littelfuse NANO² 451 Fuse, 6.3 A, 125 V","metaDescription":"045106.3MRL Littelfuse NANO² 451 surface-mount fuse, 6.3 A, 125 V AC/DC, fast blow, 50 A breaking capacity, CSA/PSE/UL approved.","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":"9.17","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":"0.0096 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"6.3 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 approvals does 045106.3MRL carry?","answer":"CSA, PSE, and UL approvals are listed. This covers North American (UL/CSA) and Japanese (PSE) regulatory acceptance for the fuse."},{"question":"What is the melting I²t of 045106.3MRL and why does it matter?","answer":"The melting I²t is 9.17 A²s. This figure is used to coordinate the fuse with downstream components — the fuse must open before the I²t withstand of the protected circuit is exceeded."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045106.3MRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045106.3MRL 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}}