H11A2M Equivalent & Substitute Parts

Part Overview

The H11A2M is an optoisolator transistor with base output manufactured by onsemi, designed for high-voltage isolation applications requiring 7500Vpk isolation rating. This component features a single-channel transistor output configuration in a 6-SMD surface mount package. The H11A2M is currently classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing system support, design updates, and procurement continuity.

Substiute Parts

H11A2M

onsemiIn Stock: 12552H11A2M Datasheet

Current PartRFQ

H11A1M

Fairchild SemiconductorIn Stock: 1970H11A1M Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the H11A2M is determined by the following critical parameters:

• Isolation Voltage Rating: The H11A2M specifies 7500Vpk isolation. Substitute parts must maintain isolation voltage at or above this level to ensure equivalent safety and performance in high-voltage isolation circuits.
• Output Configuration: The transistor with base output topology is mandatory for functional equivalence, as this determines the control and switching characteristics of the optoisolator.
• Number of Channels: Single-channel configuration is required for direct substitution.
• Current Transfer Ratio: Minimum CTR of 20% @ 10mA establishes the baseline for optical coupling efficiency.
• Saturation Voltage and Output Voltage Rating: Vce saturation of 400mV maximum and output voltage rating of 30V define the switching performance envelope.
• Switching Speed: Turn-on and turn-off times of 2µs establish the temporal response requirements for the application.
• Operating Temperature Range: The -40°C ~ 100°C range defines the thermal operating envelope.
• Mounting and Package Type: Surface mount 6-SMD configuration is required for PCB compatibility.

The H11A1M is identified as a substitute part based on shared functional topology (transistor with base output, single channel, DC input) and compatible electrical characteristics within the allowed parameter ranges for this product category.

Parameter Comparison

Engineering Selection Recommendations

The H11A1M is available as an active product from Fairchild Semiconductor, providing procurement continuity for the obsolete H11A2M. Both parts share the same functional topology (single-channel transistor with base output) and compatible electrical characteristics within the allowed parameter ranges.

Key considerations for selection:

• Isolation Voltage: The H11A1M specifies 5000Vrms isolation, which is lower than the H11A2M's 7500Vpk rating. Applications requiring the full 7500Vpk isolation margin may require additional circuit-level isolation measures or alternative component selection.
• Current Transfer Ratio: The H11A1M provides superior CTR performance at 50% minimum versus 20% for the H11A2M, resulting in improved optical coupling efficiency and potentially reduced input current requirements.
• Output Voltage Rating: The H11A1M supports 80V maximum output voltage compared to 30V for the H11A2M, providing greater flexibility in high-voltage switching applications.
• Switching Speed: The H11A1M exhibits slightly slower switching times (3µs turn-on/off versus 2µs), which may impact applications with stringent timing requirements.
• Package and Mounting: The H11A1M uses through-hole 6-DIP packaging versus surface mount 6-SMD for the H11A2M. PCB layout redesign is required for package conversion.
• Operating Temperature: The H11A1M supports an extended temperature range (-55°C ~ 110°C) compared to the H11A2M (-40°C ~ 100°C), providing broader thermal operating capability.

Both parts carry EAR99 ECCN classification and HTSUS code 8541.49.8000, maintaining equivalent export compliance status.

Frequently Asked Questions (FAQ)

Q: Can the H11A1M directly replace the H11A2M without circuit modifications?

A: Direct pin-for-pin replacement is not possible due to package differences (6-SMD surface mount versus 6-DIP through-hole). PCB layout redesign is required. Electrical compatibility exists for the shared functional parameters (single-channel transistor with base output, DC input, compatible saturation voltage and forward voltage characteristics), but isolation voltage rating differences must be evaluated against application requirements.

Q: What is the significance of the isolation voltage difference between 7500Vpk and 5000Vrms?

A: The H11A2M specifies 7500Vpk isolation, while the H11A1M specifies 5000Vrms isolation. These represent different measurement standards (peak voltage versus RMS voltage). Applications designed for the H11A2M's isolation rating should verify that the H11A1M's lower rating meets the required safety and performance margins for the specific application.

Q: How do the switching speed differences affect application performance?

A: The H11A2M provides 2µs turn-on and turn-off times, while the H11A1M provides 3µs. Applications with timing-critical switching requirements or high-frequency operation may experience performance differences. System-level timing analysis is necessary to determine if the 1µs difference is acceptable for the target application.

Q: Are there package considerations beyond physical dimensions?

A: Yes. The H11A2M uses surface mount 6-SMD packaging suitable for automated assembly and high-density PCB layouts. The H11A1M uses through-hole 6-DIP packaging, which requires different PCB footprints, assembly processes, and may occupy more board space. Component selection should align with existing manufacturing capabilities and PCB design constraints.

Q: What does the higher Current Transfer Ratio of the H11A1M mean for circuit design?

A: The H11A1M's 50% minimum CTR versus the H11A2M's 20% minimum CTR indicates superior optical coupling efficiency. This typically allows for lower input LED current to achieve the same output switching performance, potentially reducing input circuit power consumption and component stress.

Q: Are compliance and certification statuses equivalent between these parts?

A: Both parts carry identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications, maintaining equivalent export compliance status. The H11A1M's active product status provides ongoing manufacturer support and availability, whereas the H11A2M is obsolete.