4N27W

Overview

The onsemi 4N27W is a single optocoupler featuring an AlGaAs infrared LED coupled to a silicon phototransistor. It provides electrical isolation between input and output circuits, typically rated at 5000 Vrms for safety compliance. The device operates with a forward current up to 50 mA and supports a collector-emitter voltage of 80 V. It offers a minimum current transfer ratio of 100% at standard test conditions and a propagation delay of approximately 5.5 microseconds. The component is available in a 6-pin DIP package, suitable for through-hole mounting in various industrial and consumer applications requiring signal isolation.

Feature Summary

• Provides high-voltage electrical isolation between control and load circuits
• Integrates an AlGaAs infrared emitter with a silicon phototransistor detector
• Supports standard logic interface compatibility for digital signal transmission
• Designed for reliable operation across extended temperature ranges

Applications

• Industrial process control systems for sensor isolation
• Consumer appliances requiring mains isolation
• Test and measurement equipment signal conditioning
• Power supply feedback loop isolation

Procurement Notes

Verify the specific suffix code against the official datasheet to confirm package type and tape/reel specifications. Ensure the procurement channel sources genuine components from authorized distributors to avoid counterfeit devices. Check for RoHS compliance status if environmental regulations apply to your manufacturing process. Confirm lead times and availability directly with suppliers as stock levels fluctuate based on demand cycles.

Selection Notes

Select this component when cost-effective isolation is required for low-speed digital signals. Consider the current transfer ratio requirements for your specific load impedance. Evaluate the isolation voltage rating against your system's safety standards. Compare propagation delays if timing sensitivity is critical for your application design.

Part Context

The 4N27W belongs to onsemi's portfolio of general-purpose optocouplers. These devices are widely used in legacy and modern designs alike. The family emphasizes reliability and ease of integration. They serve as fundamental building blocks for isolating microcontrollers from high-voltage domains. This specific variant maintains compatibility with industry-standard pinouts.

Replacement Considerations

Direct replacements include the HCPL-2630 or PC123 series for similar performance characteristics. Verify pinout compatibility before substitution. Ensure isolation voltage ratings meet or exceed original specifications. Check current transfer ratio and propagation delay parameters for functional equivalence.