4N23U

Overview

The 4N23U is a single-channel optocoupler manufactured by TT Electronics/Optek Technology, housed in a TO-78-6 metal can package. It features an NPN phototransistor output with a base terminal for enhanced switching speed and stability. The device provides an isolation voltage of 1000 Vrms and supports a collector-emitter voltage of 35V. Key electrical parameters include a minimum current transfer ratio of 60% at 10mA forward current, a maximum collector current of 6mA, and a saturation voltage of 0.3V. Typical rise and fall times are 15µs each. The component operates within a temperature range of -55°C to +125°C.

Feature Summary

• Integrated base terminal on the NPN phototransistor output for improved switching performance
• High isolation capability with 1000 Vrms dielectric strength between input and output
• Robust thermal operation suitable for extreme environments up to 125°C

Applications

• Industrial control systems requiring galvanic isolation
• Signal transmission across isolated ground planes
• Switching applications in high-noise environments

Procurement Notes

Verify the specific suffix 'U' indicates the TO-78-6 metal can package configuration distinct from plastic variants. Confirm RoHS compliance status as some sources indicate transition periods or non-compliance for this specific military-style package. Ensure the supplier provides official datasheets matching the 4N22-24 series documentation to validate pinout and electrical limits before integration.

Selection Notes

Select this component when a base-driven phototransistor is required for faster response compared to standard unbase models. The 6mA collector current limit restricts direct drive capabilities for higher load requirements. Consider the TO-78-6 package constraints for PCB layout and thermal management. Verify that the 60% CTR minimum meets the circuit's logic threshold requirements under worst-case temperature conditions.

Part Context

This part belongs to the 4N2x family of optocouplers from TT Electronics/Optek Technology, which includes variants like the 4N22, 4N23, 4N24, and their derivatives. The 4N23U specifically denotes the version with a base terminal on the phototransistor, offering better linearity and speed than the 4N22. It shares functional similarities with the 4N24 but differs in current transfer ratio specifications and package options.

Replacement Considerations

The 4N23 is a parameter-equivalent substitute. Other family members like the 4N24 offer similar functionality but may have different CTR ranges. Verify pin compatibility and package dimensions when substituting with other TO-78-6 optocouplers.