PS2381-1 Photocouplers Renesas PS2381-1 photocoupler is an optically coupled isolator containing a GaAs LED and an NPN silicon phototransistor. The CEL PS2381-1 photocoupler is mounted in a plastic 4-LSOP package for high density applications. The package has shield effect to cut off ambient light. The CEL PS2381-1 is ideal for use in power supply and FA / OA equipment applications.