{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451007.MRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451007.MRL","canonicalUrl":"https://icboms.com/littelfuse-inc/0451007.MRL","factsUrl":"https://icboms.com/api/mcp/products/0451007.MRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, Board Mount SMD Fuse, 0451007.MRL, 7 A, 125 VAC/125 VDC, Fast Blow, 50 A breaking capacity, 2-SMD square end block package.","salesMarkdown":"## 7 A fast-blow SMD fuse for secondary-side protection The 0451007.MRL is a 7 A fast-blow surface-mount fuse from Littelfuse's NANO² 451 series, rated for 125 VAC and 125 VDC with a 50 A interrupting capacity at rated voltage. The fast-blow response means the element opens quickly on overcurrent — suited for protecting solid-state circuits and PCB traces where high inrush from capacitive loads is not expected. With a DC cold resistance of 0.009 ohms, the voltage drop at rated current is roughly 63 mV, keeping conduction losses low in a 7 A secondary-side rail. ## Package, approvals, and operating envelope Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, the 0451007.MRL mounts on the PCB surface and is available in Tape & Reel (TR suffix) for automated pick-and-place or Cut Tape for prototype quantities. Approved under CSA, PSE, and UL standards — the UL listing certifies the fuse's safety and interrupting performance for North American installations, while PSE covers Japanese market compliance. ## Melting I²t and coordination The melting I²t of 10.32 A²s defines the energy required to open the fuse element — this value is used to coordinate with downstream semiconductor surge ratings (e.g., I²t of a rectifier or MOSFET) so the fuse clears before the semiconductor fails. For a 7 A fast-blow fuse, a 10.32 I²t is typical for this package size; it means the fuse can tolerate brief inrush pulses (e.g., from a bulk capacitor bank) up to roughly 5-6 times rated current for a few milliseconds before opening.","metaTitle":"0451007.MRL Littelfuse NANO² 451 SMD Fuse, 7 A, 125 V","metaDescription":"0451007.MRL Littelfuse NANO² 451 SMD fuse, 7 A, 125 VAC/DC, fast blow, 50 A breaking capacity, UL/CSA/PSE approved, active production.","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, 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":"0.009 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"7 A","Operating Temperature":"-55°C~125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4600","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What approvals does the 0451007.MRL carry?","answer":"The fuse is approved under CSA, PSE, and UL standards, covering North American and Japanese regulatory requirements."},{"question":"What does the melting I²t of 10.32 mean for my circuit design?","answer":"The 10.32 A²s melting I²t is the energy threshold at which the fuse element opens — it is the key parameter for coordinating with downstream components so the fuse clears before a semiconductor exceeds its surge rating."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451007.MRL","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.MRL 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}}