{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1N6490US/TR","brand":"Microchip Technology","brandSlug":"microchip","productSlug":"1N6490US-TR","canonicalUrl":"https://icboms.com/microchip/1N6490US-TR","factsUrl":"https://icboms.com/api/mcp/products/1N6490US%2FTR","rawCanonicalId":null},"summary":{"shortDescription":"Microchip Technology Zener diode, 1N6490US/TR, 5.1 V nominal, ±5% tolerance, 1.5 W power dissipation, SQ-MELF D-5A package, Tape & Reel.","salesMarkdown":"## Zener voltage and power rating The 1N6490US/TR is a 5.1 V Zener diode in a surface-mount SQ-MELF package (D-5A), rated for 1.5 W continuous power dissipation. The ±5% tolerance on the nominal voltage means the actual Zener voltage sits between 4.845 V and 5.355 V — tight enough for most 5 V rail clamping or reference applications, but not a precision bandgap reference. The 1.5 W power rating is specified at the maximum operating temperature of 175°C, so derating is needed when the ambient temperature exceeds 25°C — the junction-to-ambient thermal resistance of the SQ-MELF package governs how much current the diode can sink without exceeding the junction temperature limit. Operating from -65°C to 175°C, this Zener covers military and industrial temperature extremes — suitable for avionics, downhole tools, or engine-bay electronics where the ambient can swing beyond the commercial range. The SQ-MELF (D-5A) package is a hermetic glass-sealed surface-mount body, offering better moisture resistance and thermal cycling endurance than plastic SMD packages. The Tape & Reel (TR) packaging option suits automated pick-and-place assembly. The D-5A footprint is non-standard compared to SOD-123 or SOT-23, so verify the land pattern in the assembly drawing before committing the PCB layout. ## Leakage and forward characteristics Reverse leakage is 1 µA maximum at 1 V reverse voltage — low enough that it won't load a high-impedance bias network. The forward voltage is 1.5 V maximum at 1 A forward current, typical for a Zener diode operating in the forward conduction region. Maximum Zener impedance (Zzt) is 7 Ohms at the test current — this dynamic resistance affects the voltage regulation under varying load current. A 7 Ohm Zzt at 5.1 V means a 10 mA change in current shifts the output voltage by roughly 70 mV, which is acceptable for general-purpose clamping but not for a precision shunt regulator.","metaTitle":"1N6490US/TR Zener Diode, 5.1 V, 1.5 W, SQ-MELF, Active","metaDescription":"Microchip Technology 1N6490US/TR Zener diode, 5.1 V nominal, ±5% tolerance, 1.5 W power dissipation, SQ-MELF D-5A package, -65°C to 175°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Mfr":"Microchip Technology","Series":"-","Package":"Tape & Reel (TR)","Tolerance":"±5%","Power - Max":"1.5 W","Mounting Type":"Surface Mount","Package / Case":"SQ-MELF, A","Product Status":"Active","lifecycle_stage":"eol_hot","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":"$11.0200","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/1N6490US%2FTR/alternatives.json"},"ai":{"faq":[{"question":"How can I get current pricing and availability for 1N6490US/TR?","answer":"Submit an RFQ through this listing. The part is sourced through independent distribution with full traceability."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/microchip/1N6490US-TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/microchip/1N6490US-TR 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}}