EL817

Overview

The EL817 is a single-channel transistor output optocoupler manufactured by Everlight Electronics. It integrates an infrared emitting diode with an NPN phototransistor detector, providing electrical isolation between input and output circuits. The device features a maximum collector-emitter breakdown voltage of 35 V and supports a maximum forward current of 60 mA. It offers high insulation capability with a rated isolation voltage of 5000 Vrms. The component operates within a temperature range of -55 °C to +110 °C and has a power dissipation rating of 200 mW.

Feature Summary

• Optical coupling between an infrared LED and an NPN phototransistor for signal transmission
• High dielectric strength ensuring reliable isolation between input and output terminals
• Compliance with RoHS standards and lead-free manufacturing processes
• Recognition by major safety certification bodies including UL, VDE, and CSA

Applications

• Industrial control systems requiring circuit isolation
• Signal transmission in microprocessor interfacing applications
• Switching power supply feedback loops
• Solid-state relay driver circuits

Procurement Notes

Verify the specific suffix code on the component marking to confirm the package type and lead configuration, as variations exist for through-hole and surface-mount versions. Ensure the selected variant meets the required Current Transfer Ratio (CTR) specifications for the target application. Confirm compliance with relevant regional safety certifications such as UL or VDE if mandated by the end-product design requirements.

Selection Notes

Select the appropriate package style based on the PCB assembly method; standard DIP-4 is suitable for through-hole mounting while SMD variants are designed for surface mount technology. Evaluate the required CTR range to ensure adequate switching performance under varying temperature conditions. Consider the operating temperature limits when designing for extreme environmental conditions to maintain signal integrity and device longevity.

Part Context

The EL817 belongs to the broader EL817 series of photocouplers produced by Everlight Electronics. This family includes various configurations distinguished by suffixes that indicate package type, lead spacing, and tape-and-reel options. The series is widely utilized in general-purpose isolation applications due to its compact form factor and established reliability in industrial and consumer electronics markets.

Replacement Considerations

Direct replacements include other EL817 variants from Everlight with different suffixes indicating package or packaging changes. Cross-manufacturer equivalents may be considered if pinout compatibility and electrical parameters match, though safety approvals should be re-verified.