{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"FODM121V","brand":"onsemi","brandSlug":"onsemi","productSlug":"FODM121V","canonicalUrl":"https://icboms.com/onsemi/FODM121V","factsUrl":"https://icboms.com/api/mcp/products/FODM121V","rawCanonicalId":null},"summary":{"shortDescription":"onsemi FODM121V, 1-channel DC-input transistor-output optoisolator, 3750Vrms isolation, 4-SMD Gull Wing, surface mount, -40 to +110°C","salesMarkdown":"## Isolation barrier and working voltage The FODM121V provides 3750Vrms isolation between input and output, rated for basic isolation in mains-referenced circuits up to 250V working voltage. That 3750Vrms is the test voltage, not the continuous working voltage — for reinforced isolation applications you need a part with a higher creepage package. Input side is DC-coupled, output is a single NPN phototransistor with a maximum collector-emitter voltage of 80V and continuous output current of 80mA per channel. The 400mV Vce(sat) at rated current keeps conduction loss low enough for logic-level interfaces. ## CTR spread and drive margin Current transfer ratio is specified at 5mA forward current: minimum 50%, maximum 600%. That 12:1 spread means the LED drive current must be chosen so the minimum CTR still guarantees the output saturates at the load current. At 5mA input, the output can sink 2.5mA minimum — enough for a 74HC gate input or a 5V relay coil with a series resistor. Rise and fall times are both 3µs typical, which limits the switching frequency to about 50 kHz for clean edges. Above that, the output transition becomes asymmetric and the pulse-width distortion grows. ## Sourcing and lifecycle reality onsemi lists the FODM121V as Active with ROHS3 compliance. Package is 4-SMD Gull Wing, also listed as Box — the Gull Wing leads are formed for surface-mount reflow, not through-hole. The narrow 4-pin SOIC-style body fits a 5.0mm × 4.4mm footprint with a 2.54mm lead pitch. ## Temperature range and environment Operating temperature spans -40°C to 110°C, which covers industrial enclosures, outdoor telecom cabinets, and under-hood automotive auxiliary circuits (non-AEC-Q100). The 110°C ceiling is the junction temperature limit — derate output current above 85°C ambient.","metaTitle":"FODM121V onsemi Optoisolator 3750Vrms Transistor Output","metaDescription":"FODM121V onsemi optoisolator: 3750Vrms isolation, 50-600% CTR, 80V/80mA output, -40 to +110°C, 4-SMD Gull Wing. Active production, ROHS3 compliant.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Optoisolators"],"specifications":{"Package":"Box","Input Type":"DC","Output Type":"Transistor","Mounting Type":"Surface Mount","Package / Case":"4-SMD, Gull Wing","lifecycle_stage":"eol_hot","Number of Channels":"1","Voltage - Isolation":"3750Vrms","Vce Saturation (Max)":"400mV","Operating Temperature":"-40°C ~ 110°C","Rise / Fall Time (Typ)":"3µs, 3µs","Voltage - Output (Max)":"80V","Supplier Device Package":"4-SMD","Current - Output / Channel":"80mA","Current Transfer Ratio (Max)":"600% @ 5mA","Current Transfer Ratio (Min)":"50% @ 5mA","Voltage - Forward (Vf) (Typ)":"1.3V (Max)","Current - DC Forward (If) (Max)":"50 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.88","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$0.88000","currency":"USD"},{"qty":10,"price":"$0.57100","currency":"USD"},{"qty":100,"price":"$0.37440","currency":"USD"},{"qty":1000,"price":"$0.29558","currency":"USD"},{"qty":2000,"price":"$0.27587","currency":"USD"},{"qty":5000,"price":"$0.26602","currency":"USD"},{"qty":10000,"price":"$0.26208","currency":"USD"},{"qty":25000,"price":"$0.25617","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/269c736c440b53ce097423b4caa3ac66.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is FODM121V equivalent to FODM121?","answer":"The FODM121V is a variant of the base FODM121 family. The 'V' suffix typically indicates a specific CTR bin or packaging option — confirm the CTR range (50-600% at 5mA) and the 4-SMD Gull Wing package match your BOM before substituting. onsemi does not publish a direct cross-reference; compare the datasheet CTR tables for both order codes."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/FODM121V","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/FODM121V when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T20:09:28.087Z","lastPublished":"2026-07-17T20:09:28.087Z","indexable":true}}