{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1N6490US","brand":"Microchip Technology","brandSlug":"microchip","productSlug":"1N6490US","canonicalUrl":"https://icboms.com/microchip/1N6490US","factsUrl":"https://icboms.com/api/mcp/products/1N6490US","rawCanonicalId":null},"summary":{"shortDescription":"Microchip Technology 1N6490US Zener diode, 5.1 V, 1.5 W, ±5% tolerance, SQ-MELF D-5A surface-mount package, -65°C to 175°C.","salesMarkdown":"## 5.1 V Zener in a hermetic SQ-MELF The 1N6490US is a 5.1 V Zener diode from Microchip Technology in a hermetic SQ-MELF (D-5A) surface-mount package, rated for 1.5 W continuous power dissipation. The ±5% tolerance on Vz is the standard precision band for general-purpose voltage reference or clamping — tight enough for most rail-clamp and bias circuits, though a 2% or 1% part would be needed for a precision reference where the load draws significant current through the Zzt impedance. With a maximum Zzt of 7 Ohms at the test current, regulation stiffens as the current increases — the dynamic impedance drops further above the knee, so a bias current of 10–20 mA yields a cleaner reference than running at the 1 mA minimum. Reverse leakage is specified at 1 µA max at 1 V reverse, well below the knee, confirming the junction quality for low-leakage applications. ## Hermetic package and temperature range The SQ-MELF (D-5A) is a hermetic, ceramic-based surface-mount package with a metal lid — the same construction used in JAN and MIL-S-19500 qualified devices. It handles the full -65°C to 175°C operating temperature range without the moisture sensitivity or thermal-cycle fatigue of plastic packages. This makes the 1N6490US a natural fit for avionics, satellite, downhole instrumentation, and other high-reliability environments where a plastic SOT-23 or SMA would not survive the temperature extremes or outgassing requirements. The forward voltage spec — 1.5 V max at 1 A — also means the diode can be used as a high-temperature rectifier in a pinch, though the 1.5 W power limit constrains continuous forward current to about 1 A at 25°C ambient, derating to zero at 175°C case temperature.","metaTitle":"Microchip 1N6490US Zener Diode, 5.1 V, 1.5 W, SQ-MELF","metaDescription":"Microchip Technology 1N6490US Zener diode, 5.1 V nominal, 1.5 W, ±5% tolerance, SQ-MELF D-5A package. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Mfr":"Microchip Technology","Series":"-","Package":"Bulk","Tolerance":"±5%","Power - Max":"1.5 W","Mounting Type":"Surface Mount","Package / Case":"SQ-MELF, A","Product Status":"Active","lifecycle_stage":"eol_hot","Base Product Number":"1N6490","Impedance (Max) (Zzt)":"7 Ohms","Operating Temperature":"-65°C~175°C","Supplier Device Package":"D-5A","Voltage - Zener (Nom) (Vz)":"5.1 V","Current - Reverse Leakage @ Vr":"1 µA @ 1 V","Voltage - Forward (Vf) (Max) @ If":"1.5 V @ 1 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$12.0400","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/1N6490US/alternatives.json"},"ai":{"faq":[{"question":"What package does the 1N6490US come in?","answer":"The 1N6490US is supplied in a hermetic SQ-MELF (Surface Mount MELF) package, specifically the D-5A variant per the supplier device package designation. It is a ceramic-body, metal-lid surface-mount package suitable for high-reliability and military-temperature-range applications."},{"question":"How can I order the 1N6490US or check availability?","answer":"The 1N6490US is sourced to order through independent and authorized distribution channels."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/microchip/1N6490US","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/microchip/1N6490US 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}}