The 4N33/LT part is an optocoupler manufactured by Vishay. It is a 6-pin DIP with gallium arsenide infrared LED and a light-activated silicon phototransistor. It has an isolation voltage of 5000 Vrms, a current transfer ratio (CTR) of 20 to 1000%, and a rise/fall time of 7 µs. The collector-emitter voltage rating is 30 V, while the emitter-collector voltage rating is 6 V. It has a package height of 5.08 mm and a maximum operating temperature of 85°C. The 4N33/LT part is used in a variety of applications, such as motor control, power supplies, computers, and telecommunications circuits.