{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"VOT8121AB","brand":"Vishay","brandSlug":"vishay","productSlug":"VOT8121AB","canonicalUrl":"https://icboms.com/vishay/VOT8121AB","factsUrl":"https://icboms.com/api/mcp/products/VOT8121AB","rawCanonicalId":null},"summary":{"shortDescription":"Vishay VOT8121AB phototriac optocoupler, 800 V off-state voltage, 5300 Vrms isolation, 1 kV/µs min static dV/dt, no zero-crossing, 100 mA on-state RMS current, 4-SMD Gull Wing package, -55°C to 110°C operating range.","salesMarkdown":"## 800 V off-state, 5300 Vrms isolation — a phototriac for industrial AC switching The Vishay VOT8121AB is a single-channel phototriac optocoupler designed to switch AC loads from a low-voltage logic or microcontroller signal. Its 800 V off-state voltage rating and 5300 Vrms isolation make it suitable for driving resistive or inductive loads in motor controls, solenoid valves, lighting ballasts, and solid-state relay front ends where galvanic isolation between the control side and the AC mains is required. The part comes in a 4-SMD Gull Wing package for surface-mount assembly and carries approvals from CQC, cUL, UL, and VDE, covering most global safety certification needs. ## No zero-crossing — random-phase switching for dimming and soft-start The VOT8121AB has no internal zero-crossing circuit, meaning the triac output fires immediately when the LED current exceeds the 10 mA maximum trigger threshold, regardless of the AC line phase. This random-phase behaviour is essential for phase-angle dimming of incandescent or LED lamps, soft-start of motors, and any application where the turn-on point must be controlled. For simple on/off switching of resistive loads, a zero-crossing variant would reduce conducted EMI, but this part intentionally leaves that decision to the designer. ## 1 kV/µs minimum dV/dt — noise immunity on the AC line A static dV/dt rating of 1 kV/µs minimum means the phototriac will not falsely trigger when subjected to fast voltage transients — the kind generated by relay contact bounce, motor commutation, or nearby lightning surges on the AC mains. This is a critical parameter for industrial environments where the triac must stay off until the LED is deliberately driven. The 400 µA typical holding current ensures the triac latches on once triggered and drops out cleanly when the load current falls below that threshold near the AC zero crossing. ## Active lifecycle — no end-of-life watch for new BOMs It is ROHS3 compliant.","metaTitle":"VOT8121AB Optocoupler Phototriac, 800 V Off-State, 5300 Vrms","metaDescription":"VOT8121AB phototriac optocoupler from Vishay: 800 V off-state voltage, 5300 Vrms isolation, 1 kV/µs min dV/dt, no zero-crossing, -55°C to 110°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Optoisolators"],"specifications":{"Package":"Tube","Output Type":"Triac","Mounting Type":"Surface Mount","Package / Case":"4-SMD, Gull Wing","Approval Agency":"CQC, cUL, UL, VDE","lifecycle_stage":"eol_hot","Number of Channels":"1","Static dV/dt (Min)":"1kV/µs","Current - Hold (Ih)":"400µA (Typ)","Voltage - Isolation":"5300Vrms","Voltage - Off State":"800 V","Operating Temperature":"-55°C ~ 110°C","Zero Crossing Circuit":"No","Supplier Device Package":"4-SMD","Voltage - Forward (Vf) (Typ)":"1.2V","Current - DC Forward (If) (Max)":"50 mA","Current - LED Trigger (Ift) (Max)":"10mA","Current - On State (It (RMS)) (Max)":"100 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.14","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$1.14000","currency":"USD"},{"qty":10,"price":"$0.72200","currency":"USD"},{"qty":100,"price":"$0.53440","currency":"USD"},{"qty":500,"price":"$0.49106","currency":"USD"},{"qty":1000,"price":"$0.40440","currency":"USD"},{"qty":2000,"price":"$0.38419","currency":"USD"},{"qty":5000,"price":"$0.37552","currency":"USD"},{"qty":10000,"price":"$0.36685","currency":"USD"},{"qty":25000,"price":"$0.36108","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/e11085510bee972151b7c5c68c7ea563.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Does VOT8121AB have zero-crossing drive?","answer":"No. The VOT8121AB has no zero-crossing circuit, so the triac fires on the LED trigger pulse regardless of the AC line phase. This is the correct choice for phase-angle dimming or soft-start applications."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/vishay/VOT8121AB","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/vishay/VOT8121AB 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}}