{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"FODM121R2","brand":"onsemi","brandSlug":"onsemi","productSlug":"FODM121R2","canonicalUrl":"https://icboms.com/onsemi/FODM121R2","factsUrl":"https://icboms.com/api/mcp/products/FODM121R2","rawCanonicalId":null},"summary":{"shortDescription":"onsemi FODM121R2, single-channel DC-input phototransistor optoisolator, 3750Vrms isolation, 4-SMD gull-wing package, -40°C to 110°C operating range.","salesMarkdown":"## 3750Vrms isolation in a 4-SMD gull-wing package The FODM121R2 is an onsemi single-channel phototransistor optoisolator rated for 3750Vrms isolation between input and output. The 4-SMD gull-wing package is a standard surface-mount footprint for reflow assembly, and the DC input type means the LED side is driven by a simple forward current — no AC drive conditioning needed. ## CTR spread and output drive — 50% min at 5 mA Current transfer ratio spans 50% minimum to 600% maximum at If=5 mA. The 50% floor is the design anchor: at 5 mA LED current the transistor side must sink at least 2.5 mA into the load. The wide CTR ceiling means the same part can drive a logic gate input with a weak LED drive — useful when the microcontroller pin current is tight. Output side handles up to 80V Vce and 80 mA continuous collector current. The 400 mV Vce saturation at rated current keeps conduction loss low in the on-state. Rise and fall times are 3 µs typical — fast enough for 10 kHz switching or DC-level sensing, but not for high-speed isolated data links. The FODM121R2 operates from -40°C to 110°C. The 110°C top end covers motor-drive control boards near the heatsink, outdoor base-station power supplies, and factory-floor PLC modules. The -40°C low end handles cold-start in unheated cabinets or northern-climate telecom shelters. ## Active lifecycle, ROHS3, tape-and-reel delivery Supplied in Tape & Reel (TR) or Cut Tape (CT), which matches pick-and-place feeders for volume assembly or small-batch prototyping.","metaTitle":"FODM121R2 onsemi Optoisolator – 3750Vrms, DC Input","metaDescription":"onsemi FODM121R2 optoisolator: 3750Vrms isolation, 50-600% CTR at 5mA, 80V/80mA output, -40°C to 110°C, 4-SMD gull wing. Active, ROHS3.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Optoisolators"],"specifications":{"Package":"Tape & Reel (TR); Cut Tape (CT)","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":"$0.68","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$0.68000","currency":"USD"},{"qty":10,"price":"$0.44500","currency":"USD"},{"qty":100,"price":"$0.29170","currency":"USD"},{"qty":1000,"price":"$0.23028","currency":"USD"},{"qty":2500,"price":"$0.21493","currency":"USD"},{"qty":5000,"price":"$0.20725","currency":"USD"},{"qty":12500,"price":"$0.20418","currency":"USD"},{"qty":25000,"price":"$0.19958","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/269c736c440b53ce097423b4caa3ac66.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the current transfer ratio (CTR) of FODM121R2?","answer":"The CTR is specified at 5 mA LED current: 50% minimum and 600% maximum. The 50% min is the value to use for worst-case drive calculations."},{"question":"Is FODM121R2 RoHS compliant?","answer":"Yes, onsemi lists it as ROHS3 Compliant. No exemption or conflict with common lead-free assembly profiles."},{"question":"How does FODM121R2 compare with the FODM121BR2?","answer":"Both share the same die: 3750Vrms isolation, 50-600% CTR, 80V/80mA output, 3 µs rise/fall times. The only difference is the packaging form — the FODM121R2 comes in Tape & Reel (TR) and Cut Tape (CT), while the FODM121BR2 adds a Digi-Reel® option. Functionally they are interchangeable; choose by reel preference."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/FODM121R2","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/FODM121R2 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}}