3750Vrms isolation in a 4-SOIC body
The VOS618A-8X001T is a single-channel phototransistor optocoupler from Vishay, delivering 3750Vrms of galvanic isolation in a compact 4-SOIC package. The surface-mount 4-SSOP footprint (0.173" body width) fits designs where board space is tight but a reinforced isolation barrier is still required. The output transistor can handle up to 80V and 50 mA continuous, with a saturation voltage ceiling of 400 mV — enough margin to drive a logic input or a small relay coil directly.
CTR range and switching speed for logic interface
Current transfer ratio is specified at 1 mA input: minimum 130%, maximum 260%. This 2:1 spread means the designer must verify the output transistor saturates at the lowest CTR across temperature and ageing. Typical rise and fall times are 5 µs and 7 µs, with turn-on and turn-off times of 5 µs and 8 µs — adequate for 10–100 kHz isolated signalling but not for high-speed data links. At the cold end, the LED output drops and CTR falls; at the hot end, leakage current in the phototransistor rises. The datasheet's CTR vs temperature curve (not reproduced here) is the tool to check worst-case drive margin.
Active production, ROHS3, tape-and-reel ready
Confirm the 4-SOIC footprint matches your PCB land pattern — the 0.173" body width is narrower than a standard SOIC-8, so the pad layout is specific to this package.