Avago optocouplers avago hcpl 181 000e a high performance single channel dc input phototransistor optocoupler that utilises an led optically coupled to a phototransistor packaged in a mini flat smd package that has a profile of just 2mm the volume is 30 lower that conventional packages enabling significant space saving suitable for io interfaces sequence controllers system appliances measuring instruments signal transmission etc avago hcpl 181 000e dc in transistor output optocou