4N35 Optocoupler IC: Datasheet, Pinout, Circuit Diagram & Uses


4N35 Optocoupler IC:

The 4N35 is an optocoupler that integrates an infrared LED and a phototransistor in a single package. Optocouplers are devices that allow electrical signals to be transferred between isolated circuits by using light. Here is some information on the 4N35 Optocoupler IC:


  • To access the detailed specifications, electrical characteristics, and application information, you can typically find the datasheet for the 4N35 Optocoupler from the manufacturer's website or electronic component distributors.


The pinout of a 4N35 Optocoupler usually consists of 6 pins:

  1. Anode (A): Anode of the IR LED.
  2. Cathode (K): Cathode of the IR LED.
  3. Collector (C): Collector of the phototransistor.
  4. Emitter (E): Emitter of the phototransistor.
  5. No Connection (NC): Often No Connection.
  6. Base (B): Base of the phototransistor.

Circuit Diagram:

A simple circuit diagram using a 4N35 Optocoupler might look like this:

Plain TextCopy code
Anode (A) -----  LED  /
                      \  Emitter
                       \   (E)

                   Load Resistance

Uses of 4N35 Optocoupler IC:

  1. Isolation: Provides electrical isolation between two circuits, such as protecting sensitive components from high voltages.
  2. Signal Transmission: Used for transmitting signals between different voltage potentials.
  3. Noise Immunity: Helps in reducing noise or interference in communication systems.
  4. Switching Circuits: Employed in switching circuits to control high-power devices using low-power signals.
  5. Feedback Circuits: Used in feedback circuits to provide feedback signals while maintaining isolation.
  6. Motor Control: Applied in motor control applications for safety and isolation purposes.
  7. Logic Signal Isolation: Used to isolate logic level signals in digital designs.
  8. Power Supply Feedback: Utilized for providing feedback in power supply circuits while keeping control and feedback isolated.


Overall, the 4N35 Optocoupler IC is a versatile component that finds application in various electronics projects where electrical isolation, signal transmission, noise immunity, or feedback isolation is required. By referring to the datasheet and implementing appropriate circuit configurations, you can effectively leverage the benefits of the 4N35 Optocoupler in your designs.