{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"4N25","brand":"onsemi","brandSlug":"onsemi","productSlug":"4N25","canonicalUrl":"https://icboms.com/onsemi/4N25","factsUrl":"https://icboms.com/api/mcp/products/4N25","rawCanonicalId":null},"summary":{"shortDescription":"onsemi 4N25, 1-channel optoisolator, DC input, transistor with base output, 5300Vrms isolation, 6-DIP (0.300\", 7.62mm) through-hole package, -55°C to 100°C operating range.","salesMarkdown":"## 5300Vrms isolation in a through-hole 6-DIP The onsemi 4N25 is a single-channel optoisolator with a DC input LED and a phototransistor output that brings the base terminal out. The 5300Vrms isolation rating is the headline spec — it qualifies the part for basic isolation in mains-referenced circuits, motor drives, and industrial PLC I/O where galvanic separation between control and power domains is non-negotiable. ## 20% minimum CTR and 2µs switching Minimum current transfer ratio is 20% at 10 mA forward current. That floor sets the load resistor ceiling: with a 30V output rating and 500mV Vce(sat), the phototransistor can sink enough current to drive a logic gate input or a low-power relay coil, but the 20% CTR means the LED drive must be sized to guarantee the output on-state. Turn-on and turn-off times are both 2 µs typical — fast enough for 100 kHz switching, but not for high-speed data isolation. ## Obsolete — plan a replacement now The 4N25 is marked Obsolete by onsemi. For a BOM line that still needs this footprint, the 4N35 is a common drop-in — same 6-DIP pinout, same 5300Vrms isolation, but with a higher minimum CTR (100% at 10 mA). The 4N25 remains ROHS3 compliant. Sourcing is available on an RFQ basis; confirm the quantity and lead time at quote.","metaTitle":"4N25 Optoisolator – onsemi, 5300Vrms, 6-DIP, Obsolete","metaDescription":"onsemi 4N25 optoisolator: 1-channel DC input, transistor output with base, 5300Vrms isolation, 6-DIP through-hole. Obsolete – source via RFQ for BOM fill.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Obsolete","categoryPath":["Optoisolators"],"specifications":{"Mfr":"onsemi","Series":"-","Package":"Tube","Input Type":"DC","Output Type":"Transistor with Base","Mounting Type":"Through Hole","Package / Case":"6-DIP (0.300\\\", 7.62mm)","Product Status":"Obsolete","lifecycle_stage":"eol_hot","Number of Channels":"1","Base Product Number":"4N25","Voltage - Isolation":"5300Vrms","Vce Saturation (Max)":"500mV","Operating Temperature":"-55°C ~ 100°C","Rise / Fall Time (Typ)":"-","Voltage - Output (Max)":"30V","Supplier Device Package":"6-DIP","Current - Output / Channel":"-","Current Transfer Ratio (Max)":"-","Current Transfer Ratio (Min)":"20% @ 10mA","Voltage - Forward (Vf) (Typ)":"1.18V","Turn On / Turn Off Time (Typ)":"2µs, 2µs","Current - DC Forward (If) (Max)":"100 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.6100","priceTiers":[{"qty":1,"price":"$0.44000","currency":"USD"},{"qty":10,"price":"$0.26900","currency":"USD"},{"qty":100,"price":"$0.15460","currency":"USD"},{"qty":1000,"price":"$0.12096","currency":"USD"},{"qty":2000,"price":"$0.11088","currency":"USD"},{"qty":5000,"price":"$0.10080","currency":"USD"},{"qty":10000,"price":"$0.09408","currency":"USD"},{"qty":25000,"price":"$0.09072","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/ae544ba061a6911d9506f293cac87ff7.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/4N25/alternatives.json"},"ai":{"faq":[{"question":"Is the onsemi 4N25 obsolete, and what is the replacement?","answer":"Yes, the 4N25 is listed as Obsolete. A common pin-compatible replacement is the 4N35, which shares the same 6-DIP footprint and 5300Vrms isolation but offers a higher minimum current transfer ratio (100% at 10 mA vs 20%). Confirm the CTR requirement before swapping."},{"question":"What is the difference between 4N25 and 4N35?","answer":"Both are single-channel optoisolators in 6-DIP with 5300Vrms isolation. The key difference is the minimum CTR: 4N25 is 20% at 10 mA, while the 4N35 is typically 100% at 10 mA. The 4N35 also has a wider operating temperature range (typically -55°C to 100°C, same as 4N25). Pinout is identical."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/onsemi/4N25","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/onsemi/4N25 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T20:06:56.984Z","lastPublished":"2026-07-17T20:06:56.984Z","indexable":true}}