The 4N35-M from Fairchild is a through hole general purpose phototransistor optocoupler in 6 pin DIP package. This optocoupler consist of gallium arsenide infrared emitting diode driving a silicon photo transistor. The device is mostly suitable for power supply regulators, digital logic inputs and microprocessor inputs.
Minimum current transfer ratio of 100% at IF=10A, Vce=10V
