The Vishay VOM618A-8T is a single-channel phototransistor optocoupler with a DC input LED and a 3750Vrms isolation barrier. It comes in a 4-SOP Gull Wing surface-mount package, making it a straightforward pick for galvanic isolation in industrial control, motor-drive feedback, PLC digital inputs, and power-supply secondary-side sensing. The -55°C to 110°C operating temperature range suits outdoor telecom cabinets and engine-bay electronics where the ambient can swing hard.
The current transfer ratio spans 130% to 260% at a forward current of 1 mA. That spread tells you the LED drive current and the output pull-up resistor need to be sized for the minimum CTR to guarantee the output saturates. At 1 mA forward, a minimum CTR of 130% means the output transistor can sink at least 1.3 mA — enough to pull a 10 kΩ pull-up to logic low with margin. The wide CTR band also means you don't need to bin parts; the same resistor value works across the whole production lot.
Switching speed and output ratings
Typical rise and fall times are 5 µs and 4 µs respectively, with turn-on and turn-off times of 7 µs and 6 µs. That puts this part in the medium-speed class — fine for 10 kbps digital isolation or 50/60 Hz AC zero-cross detection, but not for high-speed data links. The output transistor is rated for 80 V and 50 mA continuous, so it can drive a small relay coil or a logic input directly without a buffer transistor.
Package and mounting
The 4-SOP Gull Wing package is about as rework-friendly as optocouplers get. The leads are visible and accessible for hand-soldering or hot-air removal. The 4-SMD footprint is standard, and the Gull Wing form gives you a visual solder-joint inspection. No hidden pads, no thermal pad to worry about.
Lifecycle and compliance
The ROHS3 compliance covers the current exemption list, which matters for EU-market equipment.