4N40

Overview

The onsemi 4N40 is a single-channel optoisolator featuring an SCR output, designed for high-voltage isolation applications. It provides a robust 5300Vrms isolation voltage between the input LED and the output silicon-controlled rectifier. The device operates within a temperature range of -55°C to 100°C and supports a maximum forward current of 60 mA with a typical forward voltage of 1.1 V. The SCR output can handle a holding current of 1 mA and offers a static dV/dt rating of at least 500 V/µs. Packaged in a standard 6-DIP configuration, it ensures reliable signal transmission across isolated circuits.

Feature Summary

• Provides high-voltage electrical isolation via a 5300Vrms barrier between input and output sections.
• Features a Silicon-Controlled Rectifier (SCR) output suitable for triggering triacs or other high-power loads.
• Operates reliably across an extended industrial temperature range from -55°C to 100°C.
• Delivers fast switching performance with a maximum turn-on time of 50 µs.

Applications

• Industrial control systems requiring galvanic isolation
• Solid-state relay driver circuits
• Triac gate triggering interfaces
• Noise-immune signal transmission in harsh environments

Procurement Notes

Verify component authenticity through authorized distributors to avoid counterfeits. Confirm that the specific order matches the 4N40 part number, as variants like 4N40QT may exist. Check RoHS compliance status and REACH SVHC declarations prior to integration. Ensure storage conditions meet moisture sensitivity level requirements. Validate pinout compatibility with existing PCB footprints before finalizing procurement decisions.

Selection Notes

Select this component when high-voltage isolation and SCR output capability are required. Consider the 5300Vrms rating for safety-critical applications. Evaluate the 50 µs turn-on time against system timing constraints. Assess thermal management needs given the 450 mW power dissipation limit. Compare against alternatives if lower isolation voltages or different output types like transistors are sufficient for the design.

Part Context

The 4N40 belongs to onsemi's standard product portfolio, specifically within the optocoupler and isolation category. It utilizes silicon technology and is housed in a through-hole 6-DIP package. This series is designed for general-purpose isolation tasks where reliability and high voltage blocking are paramount. It complements other optoisolators in the lineup by offering a specialized SCR output rather than a transistor or logic gate.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Users should consult official replacement guides or contact onsemi directly for cross-reference information. Verify pin-to-pin compatibility and electrical parameter equivalence before substituting any alternative components.