TCDT11 Optocouplers, Phototransistor Output The Vishay Semiconductors TCDT1110, TCDT1101G, TCDT1102G, TCDT11020G, and TCDT1122G are phototransistors optically coupled to a gallium arsenide infrared-emitting diode in a 6-pin plastic dual inline package. The base of these Vishay Semiconductors TCDT11xx / TCDT11xxG optocouplers are not connected, providing noise immunity. The elements are mounted on one leadframe, providing a fixed distance between input and output for highest safety requirements. These Vishay Semiconductors devices are designed for use in switch-mode power supplies, line receivers, computer peripheral interface, microprocessor system interface, and circuits for safe protective separation against electrical shock. The TCDT11xx and TCDT11xxG feature isolation test voltage of 5300 Vrms and extra low coupling capacity (typical 0.2 pF).