{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1N6311US","brand":"Microchip Technology","brandSlug":"microchip","productSlug":"1N6311US","canonicalUrl":"https://icboms.com/microchip/1N6311US","factsUrl":"https://icboms.com/api/mcp/products/1N6311US","rawCanonicalId":null},"summary":{"shortDescription":"Microchip Technology 1N6311US Zener diode, 3 V nominal, 500 mW, ±5% tolerance, SQ-MELF B surface-mount package.","salesMarkdown":"The 1N6311US is a 3 V nominal Zener diode from Microchip Technology, rated at 500 mW maximum power dissipation. The ±5% tolerance on the Zener voltage means the regulation point sits between 2.85 V and 3.15 V at the specified test current — tight enough for most reference and clamping duties in low-voltage rail protection or bias generation. Maximum Zener impedance (Zzt) is 29 Ohms. A lower impedance means tighter regulation as the current changes; at 29 Ohms the 1N6311US holds the output within roughly 29 mV per mA of load variation, which is adequate for general-purpose clamping and simple shunt regulators where the load current is stable. Reverse leakage is specified at 30 µA maximum when 1 V is applied across the device. For a 3 V Zener this is a low leakage figure — the junction starts conducting well below the breakdown knee, so the part draws negligible current in circuits where the rail stays under 2 V. ## Package, temperature range, and deployment context Housed in the SQ-MELF B package (surface-mount MELF, B-size), the 1N6311US is a hermetic ceramic package with metalized end caps. The MELF form factor is common in high-reliability and military/aerospace designs where the hermetic seal prevents moisture ingress and the cylindrical body handles thermal cycling better than molded plastic SOD-123 or SOT-23 packages. At 175°C junction temperature the 500 mW power rating must be derated per the device's thermal resistance; in practice this part is suited for avionics, downhole instrumentation, and engine-bay electronics where ambient temperatures exceed 125°C. The forward voltage spec — 1.4 V maximum at 1 A forward current — confirms the die can handle short forward-current surges during reverse-polarity events or inductive kickback. The 1 A peak forward current is higher than the continuous Zener current at 500 mW (roughly 167 mA at 3 V), so the part survives brief forward overstress without failing short.","metaTitle":"Microchip 1N6311US Zener Diode, 3 V, 500 mW, SQ-MELF","metaDescription":"Microchip 1N6311US Zener diode: 3 V nom, 500 mW, ±5% tolerance, SQ-MELF B surface-mount, -65°C to 175°C. Active production, quoted 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":"500 mW","Mounting Type":"Surface Mount","Package / Case":"SQ-MELF, B","lifecycle_stage":"eol_hot","Impedance (Max) (Zzt)":"29 Ohms","Operating Temperature":"-65°C~175°C","Supplier Device Package":"B, SQ-MELF","Voltage - Zener (Nom) (Vz)":"3 V","Current - Reverse Leakage @ Vr":"30 µA @ 1 V","Voltage - Forward (Vf) (Max) @ If":"1.4 V @ 1 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/950a1a5ef1d17a0e9b75efb616fa4721.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/1N6311US/alternatives.json"},"ai":{"faq":[{"question":"What is the tolerance and power rating of the 1N6311US?","answer":"The Zener voltage tolerance is ±5%. Maximum power dissipation is 500 mW. At 3 V nominal, the continuous Zener current should not exceed approximately 167 mA to stay within the power rating at 25°C ambient."},{"question":"What compliance documentation does Microchip provide for the 1N6311US?","answer":"Microchip Technology provides RoHS and REACH compliance documentation for the 1N6311US. The hermetic SQ-MELF package does not carry UL or IEC certification markings; compliance is managed through Microchip's standard material declaration and conflict-minerals reporting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/microchip/1N6311US","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/microchip/1N6311US 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}}