H11D2M Optoisolator Equivalent & Substitute Parts

Part Overview

The H11D2M is an optoisolator transistor with base output manufactured by onsemi, rated for 7500Vpk isolation voltage in a 6-DIP package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The H11D2M provides galvanic isolation with a single transistor output channel, suitable for applications requiring high-voltage isolation with moderate current switching capability.

Substiute Parts

H11D2M

onsemiIn Stock: 12433H11D2M Datasheet

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H11D1M

onsemiIn Stock: 15708H11D1M Datasheet

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4N35

onsemiIn Stock: 979644N35 Datasheet

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4N37

Vishay Semiconductor Opto DivisionIn Stock: 190924N37 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the H11D2M is determined by the following critical parameters:

• Isolation Voltage Rating: The H11D2M specifies 7500Vpk isolation. Substitute parts must maintain isolation voltage at or above this level to ensure equivalent safety and performance margins.
• Output Configuration: All substitutes must feature transistor output with base access to maintain circuit compatibility.
• Package Type: All substitutes must use 6-DIP (0.300", 7.62mm) through-hole packaging for direct PCB compatibility.
• Number of Channels: Single-channel configuration is required.
• Current Transfer Ratio: Minimum 20% @ 10mA ensures adequate optical coupling efficiency.
• Output Current Capability: 100mA per channel is the baseline requirement.
• Maximum Output Voltage: 300V maximum output voltage rating must be maintained.

The identified substitutes are grouped based on isolation voltage rating and product status. H11D1M offers lower isolation voltage (4170Vrms) and is active, making it suitable only for applications not requiring the full 7500Vpk isolation margin. The 4N35 and 4N37 provide isolation ratings of 5300Vrms and 5000Vrms respectively, both below the H11D2M specification, and are therefore partial substitutes for reduced isolation requirements.

Parameter Comparison

Engineering Selection Recommendations

H11D1M (onsemi): This part is active and maintains the same output voltage rating (300V) and current capability (100mA) as the H11D2M. However, the isolation voltage is reduced to 4170Vrms, representing a 44% reduction from the H11D2M specification. Selection of H11D1M is appropriate only for applications where the lower isolation voltage meets system requirements and safety margins are re-evaluated.

4N35 (onsemi): This part is obsolete with isolation voltage of 5300Vrms, approximately 29% below the H11D2M rating. The maximum output voltage is significantly reduced to 30V, making it unsuitable for applications requiring the H11D2M's 300V output capability. The 4N35 offers higher current transfer ratio (100% @ 10mA) and faster switching (2µs), but these advantages do not compensate for the reduced isolation and output voltage specifications.

4N37 (Vishay Semiconductor Opto Division): This part is active with isolation voltage of 5000Vrms, approximately 33% below the H11D2M rating. Like the 4N35, the maximum output voltage is limited to 30V. The 4N37 is RoHS3 compliant and offers extended temperature range (-55°C to 100°C), but the reduced isolation voltage and output voltage make it a partial substitute only for applications with lower isolation requirements.

For applications requiring the full 7500Vpk isolation specification of the H11D2M, no direct equivalent substitute exists among the provided alternatives. Design review is necessary to determine whether reduced isolation voltage specifications are acceptable for the intended application.

Frequently Asked Questions (FAQ)

Q: Can H11D1M directly replace H11D2M in existing designs?

A: H11D1M shares the same 6-DIP package, output configuration, and current rating as H11D2M. However, the isolation voltage is reduced from 7500Vpk to 4170Vrms. Direct replacement is possible only if the application does not require the higher isolation voltage margin. System-level isolation and safety analysis must be performed before substitution.

Q: Why do 4N35 and 4N37 have lower maximum output voltage than H11D2M?

A: The 4N35 and 4N37 are designed for different application classes with lower output voltage requirements. These parts specify 30V maximum output voltage compared to H11D2M's 300V. This fundamental difference in output stage design makes them unsuitable for high-voltage switching applications.

Q: Are all substitute parts available in the same 6-DIP package?

A: Yes, all identified substitutes use the 6-DIP (0.300", 7.62mm) through-hole package, ensuring mechanical and PCB-level compatibility with H11D2M footprints.

Q: What is the significance of product status (Active vs. Obsolete)?

A: Active products have ongoing manufacturing and supply availability. H11D1M and 4N37 are active, providing better long-term procurement assurance. H11D2M and 4N35 are obsolete, indicating limited or no future availability. For new designs, active alternatives are preferred when specifications permit.

Q: How do current transfer ratios affect substitution?

A: Current transfer ratio determines optical coupling efficiency. H11D2M and H11D1M specify 20% minimum, while 4N35 and 4N37 specify 100% minimum. Higher current transfer ratio provides better optical efficiency but does not directly affect circuit compatibility if input drive current is adjusted accordingly.

Q: Can switching speed differences impact circuit performance?

A: Yes. H11D2M specifies 5µs turn-on and turn-off time. The 4N35 offers faster switching at 2µs, while 4N37 is slower at 10µs. Applications with timing-critical requirements must account for these differences in circuit design and validation.