TLP293/-4 InGaAs & Phototransistor Photocouplers Toshiba TLP293 and TLP293-4 4 InGaAs Infrared and Phototransistor Photocouplers offer 80V min. collector-emitter voltage, 50% min. current transfer ratio, 100% min. rank GB, and 3750VRMS isolation voltage. They have an operating temperature range of -55°C to +125°C. The TLP293 is a low input and high isolation type photocoupler that consists of a phototransistor optically coupled to an infrared LED in an SO4 package. The TLP293-4 consists of phototransistors optically coupled to infrared emitting diodes in an SO16 package. Toshiba TLP293 and TLP293-4 4 InGaAs Infrared and Phototransistor Photocouplers are designed for use in switching power supplies, programmable logic controllers (PLCs), and I/O interface boards.