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

Low CTR degradation
Good CTR linearity depending on forward current
Fast switching times
Temperature stable
Low coupling capacitance
High common mode interference immunity