EL817(C)-G

Overview

The EL817(C)-G is a single-channel transistor output optocoupler manufactured by Everlight Electronics. It features an infrared emitting diode optically coupled to an NPN phototransistor detector, encapsulated in a green epoxy compound. The device provides electrical isolation with a rated insulation voltage of 5000 Vrms. Key electrical parameters include a collector-emitter voltage (Vceo) of 35 V and a maximum collector current (Ic) of 50 mA. The forward voltage (Vf) is specified at 1.4 V maximum, with a forward current (If) limit of 60 mA. The Current Transfer Ratio (CTR) ranges from 200% to 400% at If=5mA. Operating temperature spans -55°C to +110°C.

Feature Summary

• Provides high-voltage electrical isolation between input and output circuits via optical coupling.
• Features a standard 4-pin DIP package suitable for through-hole mounting applications.
• Utilizes an NPN phototransistor output for digital signal transmission.

Applications

• Industrial control systems requiring signal isolation
• Microprocessor-to-peripheral interface circuits
• Switching power supply feedback loops

Procurement Notes

Verify the specific suffix '-G' corresponds to RoHS compliance requirements if environmental standards are mandatory for your assembly process. Confirm that the 4-DIP package dimensions match your PCB footprint design constraints. Ensure the 5000 Vrms isolation rating meets the safety regulations applicable to your target market, such as UL or IEC standards.

Selection Notes

Select this component when a low-cost, general-purpose transistor output optocoupler is required for DC signal isolation. The EL817(C)-G is appropriate for applications where moderate speed (microsecond range) is sufficient. Consider the CTR variation (200-400%) when designing bias networks to ensure reliable switching across all units and temperature extremes.

Part Context

The EL817 series is a widely used family of optocouplers known for their reliability in general-purpose isolation tasks. The EL817(C)-G variant specifically denotes the C-grade binning for Current Transfer Ratio and includes the '-G' suffix indicating Green/RoHS-compliant packaging. It serves as a direct replacement for older generic 4DIP optocouplers in legacy designs.

Replacement Considerations

Direct pin-compatible replacements within the same package include other EL817 variants such as EL817 or EL817-C, provided their CTR specifications align with the circuit design requirements. Verify that substitute parts maintain the same 5000 Vrms isolation voltage and 35 V collector-emitter voltage ratings.