4N26 Optocoupler DIP-6 – Phototransistor Opto-Isolator IC with Base Pin

Description

4N26 Optocoupler DIP-6 – Phototransistor Opto-Isolator IC with Base Pin

The 4N26 optocoupler is a reliable opto-isolator IC designed to provide safe electrical isolation between control and power circuits. It uses an infrared LED optically coupled to a phototransistor and includes a base pin for improved switching control and sensitivity. Housed in a standard DIP-6 through-hole package, the 4N26 is widely used in SMPS feedback circuits, industrial control boards, relays, and microcontroller signal isolation.

Applications

• SMPS feedback and regulation circuits
• Microcontroller and logic signal isolation
• Relay drive and load switching isolation
• Industrial automation and PLC inputs
• Noise and ground-loop isolation

How to Use

1. Connect a current-limiting resistor in series with the input LED.
2. Drive the LED from the control or logic side.
3. Use the phototransistor output with a pull-up resistor.
4. Optional base pin connection improves switching performance.
5. Maintain proper PCB isolation spacing for safety.