{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"4N29SR2M","brand":"onsemi","brandSlug":"onsemi","productSlug":"4N29SR2M","canonicalUrl":"https://icboms.com/onsemi/4N29SR2M","factsUrl":"https://icboms.com/api/mcp/products/4N29SR2M","rawCanonicalId":null},"summary":{"shortDescription":"onsemi 4N29SR2M, single-channel DC-input Darlington-output optoisolator, 4170Vrms isolation, 100% min CTR at 10mA, 150mA output, 6-SMD gull-wing surface-mount package.","salesMarkdown":"## Galvanic isolation with Darlington drive The 4N29SR2M is a single-channel optoisolator from onsemi that couples a DC input LED to a Darlington phototransistor output with a base terminal. The 4170Vrms isolation rating makes it suitable for breaking ground loops and protecting low-voltage logic from high-side transients in industrial controls, motor drives, and power supplies. A minimum current transfer ratio of 100% at 10mA forward current means the output can sink at least as much current as the LED draws — no gain compression at the low end. The Darlington configuration delivers a continuous output current of 150mA and a Vce saturation of 1V max, so it can drive relays, solenoids, or PLC input modules directly without a buffer transistor. ## Switching speed and load timing Turn-on time is 5µs typical, but turn-off stretches to 40µs maximum. That asymmetry caps the practical switching frequency around 12 kHz — fine for 50/60 Hz line-cycle detection, relay coil switching, or status feedback from a contactor, but not for high-speed data isolation. If your application needs symmetric switching below 10µs, the 4N38SM (transistor output, 5µs turn-on/off) is a faster alternative, though its output current is limited to 100mA. ## Active production, surface-mount package It ships in Tape & Reel or Cut Tape, which matches automated pick-and-place assembly. The 6-SMD gull-wing footprint is the surface-mount variant of the classic 4N29 — the through-hole 4N29M is electrically identical but requires manual insertion. ## Operating range and derating The operating temperature spans -40°C to 100°C, covering industrial enclosures and outdoor telecom cabinets. The maximum forward LED current is 80mA, and the typical forward voltage is 1.2V — a 220-ohm series resistor from a 5V logic rail will bias the LED at about 17mA, well within the safe zone and above the 10mA test point for the CTR spec.","metaTitle":"4N29SR2M 4170Vrms Darlington with Base","metaDescription":"onsemi 4N29SR2M optoisolator: DC input, Darlington output with base, 4170Vrms isolation, 100% min CTR, 150mA output, surface-mount 6-SMD gull wing.","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":"Darlington with Base","Mounting Type":"Surface Mount","Package / Case":"6-SMD, Gull Wing","lifecycle_stage":"eol_hot","Number of Channels":"1","Voltage - Isolation":"4170Vrms","Vce Saturation (Max)":"1V","Operating Temperature":"-40°C ~ 100°C","Voltage - Output (Max)":"30V","Supplier Device Package":"6-SMD","Current - Output / Channel":"150mA","Current Transfer Ratio (Min)":"100% @ 10mA","Voltage - Forward (Vf) (Typ)":"1.2V","Turn On / Turn Off Time (Typ)":"5µs, 40µs (Max)","Current - DC Forward (If) (Max)":"80 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.99","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$0.99000","currency":"USD"},{"qty":10,"price":"$0.64400","currency":"USD"},{"qty":100,"price":"$0.42180","currency":"USD"},{"qty":1000,"price":"$0.33300","currency":"USD"},{"qty":2000,"price":"$0.31080","currency":"USD"},{"qty":5000,"price":"$0.29970","currency":"USD"},{"qty":10000,"price":"$0.29526","currency":"USD"},{"qty":25000,"price":"$0.28860","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/3b7a0e595c13b969737948a1da9a0357.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is the 4N29SR2M RoHS compliant?","answer":"Yes, the 4N29SR2M is ROHS3 compliant, meaning it meets the latest EU restriction on hazardous substances including the four phthalates."},{"question":"What is the closest functional alternative to the 4N29SR2M?","answer":"The 4N33SM is the nearest surface-mount peer — same DC input, Darlington output with base, 4170Vrms isolation, and 150mA output current. The key difference is the turn-off time: 100µs max on the 4N33SM versus 40µs max on the 4N29SR2M. For through-hole designs, the 4N29M is electrically identical in a DIP-6 package. If you need faster switching, the 4N38SM (transistor output, 5µs turn-off) is an option but derates output to 100mA."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/4N29SR2M","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/4N29SR2M when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T20:07:01.225Z","lastPublished":"2026-07-17T20:07:01.225Z","indexable":true}}