4000Vrms isolation with Darlington gain
The Vishay IL222AT is a single-channel optocoupler that combines a DC-input LED with a photodarlington output transistor plus a base-access pin. The 4000Vrms isolation rating makes it a fit for applications where galvanic isolation is required between a low-voltage control side and a higher-voltage power or sensor side—think industrial PLC I/O modules, motor-drive feedback, or isolated switching power supplies. The Darlington output delivers a 200% minimum current transfer ratio at only 1 mA forward current, meaning the LED side draws minimal current while the output side can switch up to 30V with a Vce saturation of 1V max. That gain is what lets you drive a relay coil or a logic input from a microcontroller pin through a single resistor.
The 8-SOIC package is a common 3.90mm-wide footprint that reflows easily and keeps board area tight. Surface-mount assembly is standard for volume production, and the ROHS3 compliance avoids the REACH paperwork hassle.
ROHS3 compliant.