{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1206L450SL-VYR","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"1206L450SL-VYR","canonicalUrl":"https://icboms.com/littelfuse-inc/1206L450SL-VYR","factsUrl":"https://icboms.com/api/mcp/products/1206L450SL-VYR","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. POLY-FUSE®, LoRho series PTC resettable fuse, Type Polymeric, 1206L450SL-VYR, 4.5 A hold, 9 A trip, 6 V max, 50 A max, 1206 (3216 Metric) Concave package.","salesMarkdown":"## What the hold and trip currents mean for your circuit The 1206L450SL-VYR: The 4.5 A hold current (Ih) is the continuous DC current the PTC carries without tripping at 25 °C ambient — below this threshold the internal resistance stays at its initial 1 mOhm minimum, so the voltage drop across the part is under 5 mV at rated load. When the fault current reaches 9 A (It), the polymeric element heats and transitions to a high-resistance state within 2 seconds, clamping the current to a leakage level until power is removed or the fault clears. The post-trip resistance rises to 14 mOhm maximum — this is the resistance the circuit sees after a trip event, and it resets to the initial low value only after the device cools and power is cycled. Surface-mount termination with a concave end-cap design — the solder fillet wets the end metallization on both sides, which improves thermal coupling to the PCB copper for faster trip response under sustained overcurrent. ## Lifecycle reality and sourcing path No official successor order code is recorded from Littelfuse for this specific LoRho variant; a functional replacement requires reviewing the POLY-FUSE LoRho family for a part with matching 4.5 A hold, 6 V max, and 1206 footprint, then verifying the initial and post-trip resistance limits against the application. ## Approvals and temperature envelope Carries cURus and TUV agency approvals — the cURus mark certifies compliance with UL 1434 and CSA C22.2 No. 0.4 for polymeric PTC devices, while TUV confirms IEC 60738-1 and EN 60738-1 conformance for overcurrent protection in equipment intended for the European market.","metaTitle":"Littelfuse 1206L450SL-VYR PTC Resettable Fuse, 4.5A Hold","metaDescription":"Littelfuse 1206L450SL-VYR POLY-FUSE LoRho PTC resettable fuse, 4.5A hold current, 6V max, 1206 package. Obsolete, sourced to order. Request quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Type":"Polymeric","Series":"POLY-FUSE®, LoRho","Package":"Tape & Reel (TR) Cut Tape (CT)","Ratings":"-","Lead Spacing":"-","Time to Trip":"2 s","Current - Max":"50 A","Mounting Type":"Surface Mount","Voltage - Max":"6V","Package / Case":"1206 (3216 Metric), Concave","Product Status":"Obsolete","Approval Agency":"cURus, TUV","Thickness (Max)":"0.055\\\" (1.40mm)","lifecycle_stage":"unknown","Size / Dimension":"0.126\\\" L x 0.065\\\" W (3.20mm x 1.65mm)","Current - Trip (It)":"9 A","Height - Seated (Max)":"-","Operating Temperature":"-40°C ~ 85°C","Current - Hold (Ih) (Max)":"4.5 A","Resistance - Initial (Ri) (Min)":"1 mOhms","Resistance - Post Trip (R1) (Max)":"14 mOhms"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.1900","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/ba263e768b43be9aa2568c602b905b30.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the closest alternative to the 1206L450SL-VYR in the POLY-FUSE LoRho family?","answer":"No official successor is recorded. A functional replacement must match the 4.5 A hold current, 6 V maximum voltage, 1206 concave package, and the 1 mOhm initial / 14 mOhm post-trip resistance limits. Review the current POLY-FUSE LoRho catalog for a part meeting all four constraints; the trip current (9 A) and time-to-trip (2 s) are secondary selection criteria."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/1206L450SL-VYR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/1206L450SL-VYR when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-20T14:34:45.345Z","lastPublished":"2026-07-20T14:34:45.345Z","indexable":true}}