4N29

Overview

The onsemi 4N29 is a single-channel transistor output optocoupler featuring a photodarlington detector. It provides electrical isolation with an insulation voltage of 7500 Vrms. The device operates within a temperature range of -40°C to +100°C and is housed in a PDIP-6 package. Key electrical parameters include a maximum collector-emitter voltage of 30 V, a maximum collector current of 150 mA, and a forward current of 80 mA. The typical forward voltage is 1.5 V, with a maximum collector-emitter saturation voltage of 1 V.

Feature Summary

• Photodarlington output configuration for high gain
• High insulation voltage capability
• Wide operating temperature range

Applications

• General purpose signal isolation
• Microprocessor system interfaces
• Solid-state relay drivers

Procurement Notes

Verify the specific suffix (e.g., TM, M) as availability varies significantly across variants. Some versions are marked as obsolete or discontinued by the manufacturer. Confirm RoHS compliance status and packaging type through official datasheets before procurement. Check for active substitute part numbers if the primary variant is unavailable.

Selection Notes

Select based on required isolation voltage and package style. Ensure the photodarlington output characteristics match the load requirements. Verify thermal performance within the specified operating temperature range. Consider alternative pin-compatible devices if the standard DIP-6 form factor is unsuitable for the target application.

Part Context

The 4N29 belongs to the broader family of transistor output optocouplers from onsemi. Variants such as 4N29M and 4N29SM offer different packaging options like bulk DIP or surface mount SMD configurations. These components share core functional specifications while differing in physical footprint and manufacturing lot details.

Replacement Considerations

Official substitutes include the 4N29M and 4N29SM variants. Verify pin compatibility and electrical parameter equivalence before substitution.