Single-channel phototransistor coupler with 3750 Vrms barrier
The VOS615A-1X001T is a single-channel phototransistor optocoupler from Vishay's VOS615A series. It provides 3750 Vrms galvanic isolation between input and output, with a transistor output rated to 80 V and 50 mA continuous.
CTR range and aging margin
Current transfer ratio is specified at 40% minimum and 80% maximum, both measured at a forward current of 10 mA. The 40% floor leaves room for LED aging over the product lifetime — a common failure mode in isolated feedback loops where CTR drift can push a regulator out of regulation. Designing with the minimum CTR rather than the typical value ensures the circuit still switches correctly years into service.
Temperature range and switching speed
Rise and fall times are 3 µs and 4 µs typical, with turn-on and turn-off times both 5 µs.
Package and footprint
Housed in a 4-pin SOIC package (4.40 mm width, 0.173" body) with a 4-SSOP supplier device package designation. Surface-mount assembly compatible with standard reflow profiles.