The ILD256T is a 2-channel 8-pin Phototransistor Output Optocoupler with bidirectional AC input. It consists of two infrared emitters coupled to a silicon NPN phototransistor detector. It is well suited for telecom applications such as ring detection or off/on hook status, given its bidirectional LED input and guaranteed current transfer ratio (CTR) of 20% at IF=10mA.