{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"FOD4208SD","brand":"onsemi","brandSlug":"onsemi","productSlug":"FOD4208SD","canonicalUrl":"https://icboms.com/onsemi/FOD4208SD","factsUrl":"https://icboms.com/api/mcp/products/FOD4208SD","rawCanonicalId":null},"summary":{"shortDescription":"onsemi FOD4208SD, Optoisolator with Triac output, 1 channel, 5000 Vrms isolation, 800 V off-state, 60 µs turn-on, 10 kV/µs static dV/dt, surface mount 6-SMD gull wing package.","salesMarkdown":"## Triac output optoisolator for line-voltage switching The FOD4208SD is an onsemi optoisolator with a Triac output, rated for 5000 Vrms isolation and 800 V off-state blocking, making it suitable for switching 240 VAC or 480 VAC loads with transient margin. With a 60 µs turn-on time and no zero-crossing circuit, it fires at any point in the AC cycle, enabling phase-angle dimming, soft-start, or random-fire control in industrial and appliance applications. The single-channel device comes in a 6-SMD gull-wing package for surface-mount reflow assembly, with approvals from cUL, FIMKO, and UL. ## Parametric deep-dive: drive current, dV/dt, and temperature The LED trigger current is 2 mA maximum, allowing direct drive from 3.3 V or 5 V logic outputs without a buffer transistor — a practical advantage for microcontroller-based designs. Static dV/dt is a minimum of 10 kV/µs, providing immunity against fast voltage transients common in motor-drive, relay-coil, and solenoid circuits that could otherwise false-trigger a standard triac driver. Operating temperature spans -55°C to 100°C, covering outdoor telecom cabinets, motor control enclosures, and factory-floor equipment without derating concerns. Hold current is 500 µA typical, and forward voltage is 1.28 V typical at 30 mA maximum DC forward current, defining the LED drive budget. ## Sourcing and lifecycle status Available in Tape & Reel (TR) or Cut Tape (CT) packaging. Sourced and quoted per RFQ against your BOM quantity — confirm current pricing and lead time at quote.","metaTitle":"FOD4208SD Optoisolator Triac Output 5kVrms 800V off-state","metaDescription":"FOD4208SD onsemi optoisolator with Triac output, 5000Vrms isolation, 800V off-state, 10kV/µs dV/dt, 60µs turn-on.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Optoisolators"],"specifications":{"Package":"Tape & Reel (TR); Cut Tape (CT)","Output Type":"Triac","Turn On Time":"60µs","Mounting Type":"Surface Mount","Package / Case":"6-SMD, Gull Wing","Approval Agency":"cUL, FIMKO, UL","lifecycle_stage":"eol_hot","Number of Channels":"1","Static dV/dt (Min)":"10kV/µs","Current - Hold (Ih)":"500µA","Voltage - Isolation":"5000Vrms","Voltage - Off State":"800 V","Operating Temperature":"-55°C ~ 100°C","Zero Crossing Circuit":"No","Supplier Device Package":"6-SMD","Voltage - Forward (Vf) (Typ)":"1.28V","Current - DC Forward (If) (Max)":"30 mA","Current - LED Trigger (Ift) (Max)":"2mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$4.61","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$4.61000","currency":"USD"},{"qty":10,"price":"$3.26000","currency":"USD"},{"qty":100,"price":"$2.67040","currency":"USD"},{"qty":500,"price":"$2.25122","currency":"USD"},{"qty":1000,"price":"$2.06492","currency":"USD"},{"qty":2000,"price":"$1.97953","currency":"USD"},{"qty":5000,"price":"$1.94072","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/4508d0a74baa9082fd3b0c6c58d4edcd.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is FOD4208SD a zero-crossing optoisolator?","answer":"No, it has no zero-crossing circuit, so the triac output fires at any point in the AC cycle, enabling phase-angle control or random-fire switching."},{"question":"Can FOD4208SD be used to drive a triac directly?","answer":"The FOD4208SD itself contains a Triac output and can directly drive a load up to 800 V off-state. For higher current, it can drive an external power triac gate; the 2 mA LED trigger current and 500 µA hold current are compatible with standard triac gate drive requirements."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/FOD4208SD","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/FOD4208SD when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}