{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"4N37SM","brand":"onsemi","brandSlug":"onsemi","productSlug":"4N37SM","canonicalUrl":"https://icboms.com/onsemi/4N37SM","factsUrl":"https://icboms.com/api/mcp/products/4N37SM","rawCanonicalId":null},"summary":{"shortDescription":"onsemi 4N37SM, single-channel DC-input optoisolator, transistor-with-base output, 4170Vrms isolation, 100% min CTR at 10mA, 2µs switching, -40°C to 100°C, 6-SMD Gull Wing package, Tube.","salesMarkdown":"## 4170Vrms isolation with transistor base access The 4N37SM is a single-channel optoisolator from onsemi that provides 4170Vrms of galvanic isolation between a DC input LED and a phototransistor output with a separate base pin. This base-access transistor output gives the designer flexibility to add a base resistor for speed-up or to configure the transistor as a photodarlington by tying the base to the collector through an external resistor — a feature missing from three-terminal optoisolators. Minimum current transfer ratio of 100% at 10mA forward current guarantees the output transistor will saturate with modest LED drive, making it a reliable choice for logic-level interfacing in PLC digital inputs, motor-drive feedback, and industrial sensor isolation. ## Switching speed and temperature envelope Typical turn-on and turn-off times are both 2µs, which limits the part to signal frequencies below roughly 100 kHz. For higher-speed isolation, a logic-output optocoupler would be needed — but for 50/60 Hz mains sensing, relay-drive, or slow digital signals, this response is more than adequate. Rated for operation from -40°C to 100°C, the 4N37SM fits industrial environments such as factory-floor PLC racks, outdoor telecom cabinets, and under-hood automotive auxiliary circuits (non-AEC). The 100°C ceiling means the part should not be placed near a hot power supply without thermal margin analysis. ## Surface-mount gull-wing in tube delivery Housed in a 6-SMD Gull Wing package (supplier device package 6-SMD), the 4N37SM is designed for reflow soldering on standard PCB land patterns. The 30V maximum output voltage and 300mV Vce saturation at rated current mean the part can directly drive a 5V or 3.3V logic input without a level shifter, as long as the collector load resistor is sized appropriately. ## Active production with ROHS3 compliance ROHS3 compliant. Sourced to order against BOM quantity; current pricing and lead time confirmed at quote.","metaTitle":"4N37SM onsemi Optoisolator – 4170Vrms, Transistor Output","metaDescription":"onsemi 4N37SM optoisolator: 4170Vrms isolation, 100% min CTR at 10mA, 2µs switching, -40°C to 100°C, 6-SMD Gull Wing. Active lifecycle, ROHS3. Quote per BOM.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","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":"Active","lifecycle_stage":"eol_hot","Number of Channels":"1","Base Product Number":"4N37","Voltage - Isolation":"4170Vrms","Vce Saturation (Max)":"300mV","Operating Temperature":"-40°C ~ 100°C","Rise / Fall Time (Typ)":"-","Voltage - Output (Max)":"30V","Supplier Device Package":"6-SMD","Current - Output / Channel":"-","Current Transfer Ratio (Max)":"-","Current Transfer Ratio (Min)":"100% @ 10mA","Voltage - Forward (Vf) (Typ)":"1.18V","Turn On / Turn Off Time (Typ)":"2µs, 2µs","Current - DC Forward (If) (Max)":"60 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.6100","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$0.61000","currency":"USD"},{"qty":10,"price":"$0.40100","currency":"USD"},{"qty":100,"price":"$0.26560","currency":"USD"},{"qty":1000,"price":"$0.20505","currency":"USD"},{"qty":2000,"price":"$0.18529","currency":"USD"},{"qty":5000,"price":"$0.17293","currency":"USD"},{"qty":10000,"price":"$0.16676","currency":"USD"},{"qty":25000,"price":"$0.16429","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/d7db4dc53d56bf7e534658a700fb47e3.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is 4N37SM the same as 4N35?","answer":"No — the 4N37SM and 4N35SM are different part numbers. Both are single-channel DC-input optoisolators in the same 6-SMD Gull Wing package with the same 4170Vrms isolation, 300mV Vce saturation, and 2µs switching times. The difference is in the current transfer ratio (CTR) binning: the 4N37SM guarantees a minimum CTR of 100% at 10mA, while the 4N35SM has a different CTR spec (typically 100% min as well, but the datasheet should be checked for the exact bin). They are not drop-in replacements without verifying the CTR requirement of your circuit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/4N37SM","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/4N37SM when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T20:07:02.289Z","lastPublished":"2026-07-17T20:07:02.289Z","indexable":true}}