Vishay, SFH618A-3X017 Phototransistor Output Optocoupler, Surface Mount, 4-Pin SMD

The Vishay optocoupler have a GaAs infrared diode emitter, which is optically coupled to silicon planar phototransistor detector and is incorporated in a plastic DIP-4 or SMD package. The coupling devices are designed for signal transmission between two electrically separated circuits.

Good CTR linearity depending on forward current
Low CTR degradation
Low coupling capacitance
High common mode transient immunity