{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"CNY171FM","brand":"onsemi","brandSlug":"onsemi","productSlug":"CNY171FM","canonicalUrl":"https://icboms.com/onsemi/CNY171FM","factsUrl":"https://icboms.com/api/mcp/products/CNY171FM","rawCanonicalId":null},"summary":{"shortDescription":"onsemi CNY171FM optoisolator, 1-channel, DC input, transistor with base output, 4170Vrms isolation, 40-80% CTR at 10mA, 6-SMD Gull Wing package, Tube.","salesMarkdown":"## 4170Vrms isolation — what it means for the BOM The CNY171FM provides 4170Vrms galvanic isolation between input and output. This rating is the withstand voltage between the LED and the phototransistor — it certifies the part for reinforced insulation in mains-isolated circuits, such as AC-DC power supplies, motor drive feedback paths, and industrial sensor interfaces where the control side must be protected from the high-voltage bus. The 1-channel DC input drives the internal IR LED; the output is a phototransistor with a base terminal brought out. The base access lets the designer bias the transistor for faster switching or higher gain — a feature not available on simpler optocouplers that only expose the collector and emitter. ## CTR and switching speed — the real selection parameters Current Transfer Ratio (CTR) is specified at 40% minimum and 80% maximum, both measured at If=10mA. The 40% floor guarantees the phototransistor will saturate with a 10mA LED drive, delivering at least 4mA into the output load — enough to drive a logic gate input or a small relay coil. The 80% ceiling prevents overdrive that would slow turn-off due to stored base charge. Turn-on time is 2µs typical, turn-off 3µs typical; rise/fall times are 4µs and 3.5µs max respectively. This switching speed suits data rates up to roughly 100 kbit/s — adequate for status feedback, fault signalling, and low-speed isolated serial links, but too slow for high-speed communication like I²C or CAN. ## Output capability and temperature range The phototransistor is rated for 70V collector-emitter voltage and 50mA continuous output current. Operating temperature spans -40°C to +100°C, covering industrial and outdoor equipment enclosures.","metaTitle":"onsemi CNY171FM Optoisolator, 4170Vrms, 6-SMD Gull Wing","metaDescription":"onsemi CNY171FM optoisolator, 4170Vrms isolation, 40-80% CTR at 10mA. Obsolete — sourced to order against RFQ through independent channels.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Optoisolators"],"specifications":{"Mfr":"onsemi","Series":"-","Package":"Tube","Input Type":"DC","Output Type":"Transistor with Base","Mounting Type":"Surface Mount","Package / Case":"6-SMD, Gull Wing","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Number of Channels":"1","Base Product Number":"CNY171","Voltage - Isolation":"4170Vrms","Vce Saturation (Max)":"400mV","Operating Temperature":"-40°C ~ 100°C","Rise / Fall Time (Typ)":"4µs, 3.5µs (Max)","Voltage - Output (Max)":"70V","Supplier Device Package":"6-SMD","Current - Output / Channel":"50mA","Current Transfer Ratio (Max)":"80% @ 10mA","Current Transfer Ratio (Min)":"40% @ 10mA","Voltage - Forward (Vf) (Typ)":"1.35V","Turn On / Turn Off Time (Typ)":"2µs, 3µs","Current - DC Forward (If) (Max)":"60 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/dbff72ad709f03fb6695b1cadd7ed9fe.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/CNY171FM/alternatives.json"},"ai":{"faq":[{"question":"What is the closest pin-compatible alternative to the CNY171FM?","answer":"The base product number is CNY171, and the CNY171FM is a specific variant in the 6-SMD Gull Wing package. For a functional replacement, consider the CNY17F series (same pinout, similar CTR) or the 4N35 family — both available in 6-SMD Gull Wing — but confirm the CTR bin and isolation voltage match the BOM requirement."},{"question":"What compliance documentation does onsemi provide for the CNY171FM?","answer":"Standard onsemi optoisolator documentation includes RoHS and REACH compliance declarations, UL recognition (file E90700 for the CNY17 series), and a datasheet with isolation test procedures per IEC 60747-5-5."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/CNY171FM","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/CNY171FM when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-21T06:25:07.778Z","lastPublished":"2026-07-21T06:25:07.778Z","indexable":true}}