4N25X Optoisolator Equivalent & Substitute Parts

Part Overview

The 4N25X is an optoisolator transistor with base output manufactured by Isocom Components 2004 LTD. This component provides galvanic isolation up to 5300Vrms with a single channel configuration in a 6-DIP through-hole package. The device is currently active in production and widely used in industrial control, power management, and signal isolation applications. Equivalent substitute parts are identified based on matching electrical specifications and mechanical compatibility to support component procurement flexibility and supply chain continuity.

Substiute Parts

4N25X

Isocom Components 2004 LTDIn Stock: 12014N25X Datasheet

Current PartRFQ

H11A2X

Isocom ComponentsIn Stock: 1310H11A2X Datasheet

Parametric EquivalentRFQ

H11A3X

Isocom ComponentsIn Stock: 1809H11A3X Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 4N25X are qualified based on the following critical parameters that determine functional and mechanical compatibility:

• Voltage - Isolation: 5300Vrms (must match exactly)
• Number of Channels: 1 (must match exactly)
• Output Type: Transistor with Base (must match exactly)
• Current Transfer Ratio (Min): 20% @ 10mA (must match or exceed)
• Voltage - Output (Max): 30V (must match or exceed)
• Current - Output / Channel: 50mA (must match or exceed)
• Package / Case: 6-DIP (0.300", 7.62mm) (must match exactly)
• Mounting Type: Through Hole (must match exactly)
• Operating Temperature: -55°C ~ 100°C (must match or exceed)

The substitute parts H11A2X and H11A3X meet all critical electrical and mechanical parameters. Minor variations in Vce Saturation (400mV vs. 500mV) represent improved performance characteristics and do not restrict substitution.

Parameter Comparison

Engineering Selection Recommendations

Both H11A2X and H11A3X are direct parametric equivalents to the 4N25X. All three parts maintain identical isolation voltage, channel configuration, output type, and package specifications. Both substitute parts are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements. The improved Vce Saturation specification (400mV) in H11A2X and H11A3X represents enhanced performance without introducing compatibility concerns. Selection between these substitutes may be based on inventory availability and procurement lead times, as electrical performance is equivalent for standard applications.

Frequently Asked Questions (FAQ)

Q: Can H11A2X or H11A3X be used as direct replacements for 4N25X in existing designs?

A: Yes. Both H11A2X and H11A3X are parametric equivalents meeting all critical electrical and mechanical specifications. The 6-DIP through-hole package, isolation voltage, channel count, output type, and operating temperature range are identical. Pin configuration compatibility should be verified against the specific application schematic.

Q: What is the significance of the Vce Saturation difference (500mV vs. 400mV)?

A: The lower Vce Saturation in H11A2X and H11A3X indicates improved transistor saturation characteristics, resulting in lower voltage drop across the output transistor. This represents enhanced performance and does not restrict substitution.

Q: Are all three parts suitable for high-voltage isolation applications?

A: Yes. All three parts provide 5300Vrms isolation voltage and are designed for galvanic isolation in industrial control, power management, and signal isolation circuits.

Q: Do package and mounting specifications differ between these parts?

A: No. All three parts use identical 6-DIP (0.300", 7.62mm) through-hole packages and are mounted using the same PCB footprint and assembly process.

Q: Are there any compliance or regulatory differences between these parts?

A: No. All three parts are ROHS3 compliant, REACH unaffected, and carry identical MSL ratings of 1 (Unlimited), ensuring equivalent compliance status for procurement and assembly.