4N25S-M is an optocoupler which is the result of a combination of gallium arsenide infrared diode with a phototransistor. 4N25S-M is capable of producing isolation voltage of 7500 Vrms and disapasi power of 150 mW. 4N25S-M is commonly used in power supply regulator, input microprocessors, digital logic inputs, and so forth.
