The SFH6106-4 is a High Reliability Phototransistor Output Optocoupler features a high current transfer ratio, low coupling capacitance and high isolation voltage. This coupler has a GaAs infrared diode emitter, which is optically coupled to a silicon planar phototransistor detector. The coupling device is designed for signal transmission between two electrically separated circuits. This version complies with IEC 60950 (DIN VDE 0805) for reinforced insulation up to an operation voltage of 400Vrms or DC.