{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"MOC3021SM","brand":"onsemi","brandSlug":"onsemi","productSlug":"MOC3021SM","canonicalUrl":"https://icboms.com/onsemi/MOC3021SM","factsUrl":"https://icboms.com/api/mcp/products/MOC3021SM","rawCanonicalId":null},"summary":{"shortDescription":"onsemi MOC3021SM, 1-channel optoisolator with triac output, 4170 Vrms isolation, 400 V off-state, non-zero-crossing, 6-SMD gull wing package, tube","salesMarkdown":"## Triac-output optoisolator for AC load switching The MOC3021SM from onsemi is a 1-channel optoisolator with a triac output rated for 400 V off-state voltage and 4170 Vrms isolation between input and output. It has no zero-crossing circuit, so the triac can be triggered at any point in the AC cycle — useful for phase-control applications like dimmers, motor speed controllers, and soft-start circuits. The LED forward voltage is 1.15 V typical, and the maximum LED trigger current (Ift) is 15 mA. This means a standard 5 V logic output can drive it through a series resistor; the hold current is 100 µA typical, so the triac stays latched once triggered until the load current drops below that threshold. Housed in a 6-SMD gull wing package, the MOC3021SM is suited for surface-mount assembly on mixed-signal boards where the optoisolator bridges the low-voltage control side and the high-voltage AC load side. The package is supplied in tube, not tape and reel. ## Active lifecycle and sourcing position The base product number is MOC302; the 'SM' suffix denotes the surface-mount gull wing package. If your board uses the through-hole version (MOC3021), the pin functions are the same, but the footprint differs — the SM variant requires a 6-SMD land pattern.","metaTitle":"MOC3021SM onsemi Optoisolator, Triac Output, 4170 Vrms","metaDescription":"onsemi MOC3021SM optoisolator with triac output, 4170 Vrms isolation, 400 V off-state, non-zero-crossing. Active production, 6-SMD gull wing package.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Optoisolators"],"specifications":{"Mfr":"onsemi","Series":"-","Package":"Tube","Output Type":"Triac","Turn On Time":"-","Mounting Type":"Surface Mount","Package / Case":"6-SMD, Gull Wing","Product Status":"Active","Approval Agency":"UL","lifecycle_stage":"eol_hot","Number of Channels":"1","Static dV/dt (Min)":"-","Base Product Number":"MOC302","Current - Hold (Ih)":"100µA (Typ)","Voltage - Isolation":"4170Vrms","Voltage - Off State":"400 V","Operating Temperature":"-40°C ~ 85°C","Zero Crossing Circuit":"No","Supplier Device Package":"6-SMD","Voltage - Forward (Vf) (Typ)":"1.15V","Current - DC Forward (If) (Max)":"60 mA","Current - LED Trigger (Ift) (Max)":"15mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.7300","priceTiers":[{"qty":1,"price":"$0.73000","currency":"USD"},{"qty":10,"price":"$0.47500","currency":"USD"},{"qty":100,"price":"$0.31150","currency":"USD"},{"qty":1000,"price":"$0.24588","currency":"USD"},{"qty":2000,"price":"$0.22949","currency":"USD"},{"qty":5000,"price":"$0.22130","currency":"USD"},{"qty":10000,"price":"$0.21802","currency":"USD"},{"qty":25000,"price":"$0.21310","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/12f74b3254c1e0370a4fb6eb3d6dbd88.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/MOC3021SM/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between MOC3021SM and MOC3021?","answer":"The MOC3021 is the through-hole DIP version; the MOC3021SM is the surface-mount gull wing variant. Electrical specs — 400 V off-state, 4170 Vrms isolation, 15 mA max Ift — are identical. The pin functions are the same, but the PCB footprint differs."},{"question":"Does MOC3021SM require an external snubber?","answer":"The datasheet recommends a snubber circuit (typically a series RC) across the triac output when driving inductive loads like motors or relays, to limit the rate of rise of off-state voltage (dV/dt) that could otherwise trigger the triac falsely. The exact RC values depend on the load characteristics."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/MOC3021SM","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/MOC3021SM 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}}