Description

The K4N26 is a single-channel phototransistor optocoupler, manufactured by Everlight Electronics, based on the industry-standard 4N26 family design. It consists of a Gallium Arsenide infrared emitting LED optically coupled to a silicon NPN phototransistor, providing electrical isolation between input and output circuits while still allowing signal transfer — a fundamental building block for isolating control signals from power circuits.

Housed in the industry-standard DIP-6 package, the K4N26 interfaces easily with common logic families and is widely used wherever electrical isolation between two circuits is needed, without an isolation test voltage typically in the 5000VRMS range for this device family. The phototransistor output includes a base connection, giving designers added flexibility to adjust switching speed and sensitivity in the output stage if needed.

This type of optocoupler is a staple in power electronics and control circuit design, commonly used for AC mains detection, reed relay driving, switch-mode power supply feedback isolation, logic ground isolation, and general signal isolation between high-voltage and low-voltage sections of a circuit.

Key Specifications

• Type: Single-channel phototransistor optocoupler (with base connection)
• Manufacturer: Everlight Electronics
• Package: DIP-6 (through-hole)
• Isolation Voltage: ~5000VRMS (typical for 4N26 family)
• Input: Gallium Arsenide Infrared LED
• Output: Silicon NPN phototransistor
• Interfaces with common logic families
• Low input-output coupling capacitance for noise rejection

Common Applications

• AC mains detection
• Reed relay driving
• Switch-mode power supply (SMPS) feedback isolation
• Logic ground isolation
• Telephone ring detection
• General signal isolation between high-voltage and low-voltage circuits

Package Includes

• 1 x Everlight K4N26 Optocoupler (DIP-6)