A phototransistor optocoupler is formed by an infrared light emitter device (IR-LED) (Gallium Arsenide (GaAs)) and a light detector device (phototransistor), both optically coupled and typically encapsulated in a 4-pin package, which is offered in different mechanical dimensions and. A phototransistor optocoupler is formed by an infrared light emitter device (IR-LED) (Gallium Arsenide (GaAs)) and a light detector device (phototransistor), both optically coupled and typically encapsulated in a 4-pin package, which is offered in different mechanical dimensions and. A: Optocouplers are well known as optoisolators providing an isolated galvanic barrier between the input and output utilizing infrared light. On the input side an infrared light emitting diode is used with all optocoupler types. The most. An optocoupler, also known as photocoupler or opto-isolator, is a device which can transfer an electrical signal across two galvanically-isolated circuits by way of optical coupling. Unlike transformers or capacitors, which can only transfer AC signals across the isolation barrier, optocouplers can. As you might guess, isolation is a key factor when it comes to optocouplers. Optocouplers are used in many electronic devices, from mobile electronics to household electronics.
