4N29SM

Overview

The 4N29SM is a single-channel optoisolator manufactured by onsemi, featuring a Darlington transistor output with an integrated base terminal. It provides high isolation voltage of 4170Vrms and supports a maximum forward current of 80 mA. The device operates within a temperature range of -40°C to 100°C and utilizes a 6-SMD鸥翼 package. Key electrical parameters include a collector-emitter saturation voltage of 1V max, a typical turn-on time of 5µs, and a maximum turn-off time of 40µs. The minimum current transfer ratio is 100% at 10mA input.

Feature Summary

• Integrates a Darlington transistor output with a dedicated base pin for enhanced control and switching speed.
• Provides robust electrical isolation capability rated at 4170Vrms between input and output circuits.
• Designed for surface-mount installation in compact electronic assemblies.

Applications

• General-purpose signal isolation in industrial control systems
• Interface circuits for microcontrollers and logic families
• Switching applications requiring moderate speed performance

Procurement Notes

Verify the specific ordering suffix and package variant against the official onsemi datasheet to ensure compatibility with design requirements. Confirm RoHS compliance status and material declarations prior to procurement. Check for any recent Product Change Notifications (PCN) regarding assembly location or specifications. Ensure the selected component matches the required thermal and electrical ratings for the intended application environment.

Selection Notes

Select this component when a Darlington output configuration with base access is required for improved switching characteristics. Consider the 4170Vrms isolation rating for safety-critical applications. Evaluate the 5µs/40µs timing parameters against system speed requirements. Verify that the 6-SMD鸥翼 package fits the PCB layout constraints. Compare current transfer ratio specifications with load requirements.

Part Context

The 4N29SM belongs to the 4N29 family of photodarlington optocouplers produced by onsemi. This series is widely recognized for its reliability in general-purpose isolation tasks. The SM suffix indicates a surface-mount device variant, distinguishing it from through-hole DIP packages. The component leverages onsemi's established manufacturing processes for optical isolators.

Replacement Considerations

Consult official substitution lists for direct equivalents. Generic replacements may differ in isolation voltage or current transfer ratio. Verify pinout compatibility and package dimensions before integrating alternative components into existing designs.