H11A2 Optoisolator Equivalent & Substitute Parts

Part Overview

The H11A2 is an optoisolator transistor with base output manufactured by onsemi, rated for 5300Vrms isolation voltage in a 6-DIP through-hole package. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and new design implementations. The H11A2 provides galvanic isolation for low-speed switching applications requiring DC input control and transistor output with accessible base terminal.

Substiute Parts

H11A2

onsemiIn Stock: 1577H11A2 Datasheet

Current PartRFQ

4N25-000E

Broadcom LimitedIn Stock: 30614N25-000E Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the H11A2 optoisolator is determined by the following critical parameters:

• Package compatibility: 6-DIP through-hole form factor with 0.300" (7.62mm) pitch
• Output configuration: Transistor with base terminal for circuit flexibility
• Isolation voltage rating: Minimum 2500Vrms acceptable for applications not requiring the full 5300Vrms specification
• Current transfer ratio: Minimum 20% @ 10mA input current
• Maximum output voltage: 30V rating
• Operating temperature range: -55°C to 100°C
• Input type: DC control signal
• Mounting method: Through-hole PCB assembly

The 4N25-000E qualifies as a substitute based on matching package, output type, and core electrical parameters, with the primary trade-off being reduced isolation voltage (2500Vrms versus 5300Vrms).

Parameter Comparison

Engineering Selection Recommendations

H11A2 to 4N25-000E Substitution Criteria:

The 4N25-000E is suitable as a substitute for the H11A2 in applications where the isolation voltage requirement does not exceed 2500Vrms. Both components share identical package geometry, output configuration, and operating temperature range, enabling direct PCB footprint compatibility.

Key considerations for substitution:

• The 4N25-000E is currently in active production status, ensuring long-term availability and supply chain stability compared to the obsolete H11A2.
• Isolation voltage is reduced from 5300Vrms to 2500Vrms; applications requiring higher isolation must retain the H11A2 or identify alternative high-voltage optoisolators.
• Forward current maximum is slightly lower (80mA versus 100mA) on the 4N25-000E; verify input drive capability for the specific application.
• Vce saturation is marginally higher (500mV versus 400mV) on the 4N25-000E; confirm output switching performance meets circuit requirements.
• Both components comply with REACH regulations and carry EAR99 export classification.
• Both components feature MSL Level 1 (Unlimited) moisture sensitivity, requiring no special handling during storage or assembly.

Frequently Asked Questions (FAQ)

Q: Can the 4N25-000E directly replace the H11A2 in all applications?

A: Direct replacement is possible only in applications where the isolation voltage requirement is 2500Vrms or lower. If your circuit design specifies 5300Vrms isolation, the 4N25-000E does not meet this requirement. Verify the isolation voltage specification in your system design documentation before substitution.

Q: Are the package dimensions identical between H11A2 and 4N25-000E?

A: Yes. Both components use the 6-DIP (0.300", 7.62mm) through-hole package, enabling identical PCB footprint and pin spacing. No layout modifications are required for physical installation.

Q: What is the difference in switching speed between these optoisolators?

A: The H11A2 specifies 2µs turn-on and turn-off time. The 4N25-000E specifies 3µs rise and fall time. For applications with strict timing requirements below 3µs, verify that the 4N25-000E meets your circuit performance specifications.

Q: Why is the H11A2 classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The 4N25-000E, classified as active, represents a current production alternative with comparable functionality and ongoing supply availability.

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

A: Both components are REACH Unaffected and carry EAR99 export classification. Both feature MSL Level 1 (Unlimited) moisture sensitivity. No compliance barriers exist for substitution from a regulatory standpoint.

Q: What is the maximum forward current difference, and does it affect circuit design?

A: The H11A2 supports 100mA maximum forward current; the 4N25-000E supports 80mA. If your input LED drive circuit exceeds 80mA, the 4N25-000E cannot be used. Confirm your input current specification is within the 80mA limit before substitution.