The TOSHIBA TLP781 consists of a silicone photo?transistor optically coupled to a gallium arsenide infrared emitting diode in a four lead plastic DIP (DIP4) with having high isolation voltage(AC: 5kVRMS (min)).

The TOSHIBA TLP621, ?2 and ?4 consists of a photo?transistor optically coupled to an infrared emitting diode.