{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"IL205AT","brand":"Vishay","brandSlug":"vishay","productSlug":"IL205AT","canonicalUrl":"https://icboms.com/vishay/IL205AT","factsUrl":"https://icboms.com/api/mcp/products/IL205AT","rawCanonicalId":null},"summary":{"shortDescription":"Vishay IL205AT optocoupler, DC input, transistor with base output, 4000Vrms isolation, 8-SOIC surface mount, 40-80% CTR at 10mA.","salesMarkdown":"## Isolation barrier and signal transfer The IL205AT: The 8-SOIC package keeps the creepage distance short, so the isolation voltage is the spec to watch for reinforced insulation in mains-tied equipment. Current transfer ratio runs 40% minimum to 80% maximum at 10 mA forward current. That 2:1 spread means the LED drive current must be set for the low end of the CTR band to guarantee the output saturates over temperature and lifetime — 10 mA into the LED gives you at least 4 mA of collector current at the output transistor, which is enough to pull a 5V logic input low through a 1 kΩ pull-up. ## Switching speed and output drive Turn-on and turn-off times are both 3 µs typical. That 3 µs propagation delay limits the data rate to roughly 115 kHz in a digital isolator role — fine for 24V DC sensor readback at 1 kHz update rates, but too slow for a 1 MHz fieldbus coupler. The transistor-with-base output lets you add a base-emitter resistor to speed up turn-off at the cost of reduced CTR, a trick worth knowing if you need to squeeze 200 kHz out of this part. Output transistor can handle up to 70 V on the collector and saturates at 400 mV max with the base open. That 70 V ceiling covers 48 V industrial rails and 24 V with surge margin; the 400 mV Vce(sat) at 10 mA collector current means the output drops less than half a volt when driving a 5V CMOS input. ## Temperature range and forward drive Operating temperature spans -55°C to 100°C — the -55°C low end covers cold-start in unheated enclosures and outdoor telecom cabinets. The 100°C ceiling is below the 125°C automotive grade, so this part is fit for industrial control cabinets and HVAC panels but not for under-hood engine bay duty without derating the LED current above 85°C. Forward voltage is 1.3 V typical at 10 mA, and the maximum continuous forward current is 60 mA. The 1.3 V Vf means a 3.3 V logic output can drive the LED through a 200 Ω resistor with 10 mA headroom; the 60 mA limit is generous enough that the LED won't limit the design — the CTR spread and thermal derating will. ## Active production and compliance The supplier device package is 8-SOIC, so the land pattern matches industry-standard SOIC-8 with 1.27 mm pitch. RoHS3 compliant per the lifecycle record — no exemption declarations needed for EU BOMs. The input type is DC, meaning the LED is a standard infrared diode, not an AC-input part with anti-parallel diodes; polarity matters on the PCB layout.","metaTitle":"Vishay IL205AT Optocoupler, 4kV Isolation, 8-SOIC","metaDescription":"Vishay IL205AT optocoupler: 4000Vrms isolation, 40-80% CTR at 10mA, 3µs switching, -55 to 100°C. Active, RoHS3. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Package":"Tape & Reel (TR); Cut Tape (CT)","Input Type":"DC","Output Type":"Transistor with Base","Mounting Type":"Surface Mount","Package / Case":"8-SOIC (0.154\\\", 3.90mm Width)","lifecycle_stage":"eol_hot","Number of Channels":"1","Voltage - Isolation":"4000Vrms","Vce Saturation (Max)":"400mV","Operating Temperature":"-55°C ~ 100°C","Voltage - Output (Max)":"70V","Supplier Device Package":"8-SOIC","Current Transfer Ratio (Max)":"80% @ 10mA","Current Transfer Ratio (Min)":"40% @ 10mA","Voltage - Forward (Vf) (Typ)":"1.3V","Turn On / Turn Off Time (Typ)":"3µs, 3µs","Current - DC Forward (If) (Max)":"60 mA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.08","priceTiers":[{"qty":1,"price":"$1.08000","currency":"USD"},{"qty":10,"price":"$0.70200","currency":"USD"},{"qty":100,"price":"$0.45990","currency":"USD"},{"qty":1000,"price":"$0.36308","currency":"USD"},{"qty":2000,"price":"$0.33887","currency":"USD"},{"qty":6000,"price":"$0.32677","currency":"USD"},{"qty":10000,"price":"$0.32193","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/49fb652eaf2ef7146c0efab1199a7a59.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/IL205AT/alternatives.json"},"ai":{"faq":[{"question":"What is the current transfer ratio range for the IL205AT?","answer":"The IL205AT has a CTR range of 40% minimum to 80% maximum, both specified at 10 mA forward current. Design the LED drive for the 40% minimum to guarantee the output transistor saturates over the full temperature range and lifetime."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/vishay/IL205AT","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/vishay/IL205AT when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}