{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0603L004YR","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0603L004YR","canonicalUrl":"https://icboms.com/littelfuse-inc/0603L004YR","factsUrl":"https://icboms.com/api/mcp/products/0603L004YR","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse POLY-FUSE®, 0603L series, PTC resettable fuse, 0603L004YR, 40 mA hold, 120 mA trip, 24 V max, 0603 SMD concave package.","salesMarkdown":"## 40 mA hold current in a 0603 footprint The Littelfuse 0603L004YR is a polymeric PTC resettable fuse from the POLY-FUSE 0603L series, rated for 40 mA hold current and 120 mA trip current at 24 V max. In a 0603 (1608 metric) concave surface-mount package, it trips in 1 second at 20 A max fault current. ## Resistance and temperature envelope Initial resistance (Ri) is 4 Ohms minimum; after tripping, the post-trip resistance (R1) rises to 40 Ohms maximum — the ratio tells you the voltage drop across the device in the latched state is about 1.6 V at 40 mA, which is well within the 24 V rail budget. ## Active production and approvals Littelfuse lists the 0603L004YR as Active in its product lifecycle. It carries cURus and TUV agency approvals, so it is accepted in North American and European equipment without additional safety agency review.","metaTitle":"0603L004YR Littelfuse POLY-FUSE PTC Resettable Fuse, 40 mA","metaDescription":"0603L004YR Littelfuse POLY-FUSE PTC resettable fuse, 40 mA hold, 120 mA trip, 24 V max, 0603 SMD. Active production, cURus/TUV. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Type":"Polymeric","Series":"POLY-FUSE®, 0603L","Package":"Tape & Reel (TR) Cut Tape (CT)","Ratings":"-","Lead Spacing":"-","Time to Trip":"1 s","Current - Max":"20 A","Mounting Type":"Surface Mount","Voltage - Max":"24V","Package / Case":"0603 (1608 Metric), Concave","Product Status":"Active","Approval Agency":"cURus, TUV","Thickness (Max)":"0.030\\\" (0.75mm)","lifecycle_stage":"unknown","Size / Dimension":"0.063\\\" L x 0.032\\\" W (1.60mm x 0.80mm)","Current - Trip (It)":"120 mA","Height - Seated (Max)":"-","Operating Temperature":"-40°C ~ 85°C","Current - Hold (Ih) (Max)":"40 mA","Resistance - Initial (Ri) (Min)":"4 Ohms","Resistance - Post Trip (R1) (Max)":"40 Ohms"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.0300","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/e4b6b6d09813d8b80152762a3dffab34.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is 0603L004YR's listed type and series?","answer":"It is a Polymeric PTC resettable fuse from the POLY-FUSE, 0603L series."},{"question":"What compliance documentation does Littelfuse provide for 0603L004YR?","answer":"The device carries cURus and TUV agency approvals. RoHS and REACH compliance documentation is standard for the POLY-FUSE series."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0603L004YR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0603L004YR 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}}