H11B255SD Equivalent & Substitute Parts

Part Overview

The H11B255SD is an optoisolator Darlington with base output manufactured by onsemi, featuring 5300Vrms isolation voltage in a 6-SMD surface mount package. This component provides galvanic isolation for single-channel DC input applications with Darlington output configuration and integrated base connection.

The H11B255SD is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications currently utilizing this component.

Substiute Parts

H11B255SD

onsemiIn Stock: 779H11B255SD Datasheet

Current PartRFQ

H11B1SR2M

onsemiIn Stock: 4411H11B1SR2M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the H11B255SD is constrained by the following critical parameters:

Mandatory Compatibility Parameters:

• Single-channel optoisolator configuration
• Darlington output with base connection
• 6-SMD surface mount package with gull wing leads
• DC input type
• Isolation voltage rating (minimum 4170Vrms acceptable for applications not requiring full 5300Vrms)
• Output voltage rating (minimum 30V acceptable for applications not exceeding this level)
• Vce saturation characteristics (1V maximum)
• Turn-on/turn-off timing window (25µs/18µs nominal)

The H11B1SR2M qualifies as a substitute based on matching package geometry, output configuration, and core isolation architecture. However, this substitute operates at reduced isolation voltage (4170Vrms versus 5300Vrms) and reduced maximum output voltage (30V versus 55V), making it suitable only for applications within these lower parameter boundaries.

Parameter Comparison

Engineering Selection Recommendations

The H11B1SR2M is the identified substitute for the obsolete H11B255SD. Selection of this substitute requires verification that the application operates within the following reduced parameter boundaries:

• Isolation voltage requirement does not exceed 4170Vrms
• Output voltage does not exceed 30V
• Operating temperature range remains within -40°C to 100°C (upper limit unchanged; lower limit raised from -55°C)

The H11B1SR2M carries Active product status and ROHS3 compliance, providing supply chain continuity and regulatory alignment. The substitute maintains identical package geometry, output configuration, and switching timing characteristics, enabling direct PCB layout compatibility.

Applications requiring the full 5300Vrms isolation voltage of the original H11B255SD cannot use the H11B1SR2M as a substitute and require alternative component evaluation.

Frequently Asked Questions (FAQ)

Q: Can the H11B1SR2M replace the H11B255SD in all applications?

A: No. The H11B1SR2M operates at 4170Vrms isolation voltage compared to the H11B255SD's 5300Vrms. Substitution is valid only for applications where the isolation voltage requirement does not exceed 4170Vrms and the output voltage does not exceed 30V.

Q: Are the packages physically identical?

A: Yes. Both components use 6-SMD surface mount packages with gull wing leads, enabling direct PCB layout compatibility without redesign.

Q: What is the difference in current transfer ratio between these parts?

A: The H11B255SD specifies 100% CTR at 10mA input current. The H11B1SR2M specifies 500% CTR at 1mA input current. These represent different measurement conditions and reflect different device characteristics; direct comparison requires application-specific analysis.

Q: Does the H11B1SR2M support the full temperature range of the original part?

A: No. The H11B1SR2M operates from -40°C to 100°C, while the H11B255SD operates from -55°C to 100°C. Applications requiring operation below -40°C cannot use the H11B1SR2M.

Q: What is the packaging difference between these parts?

A: The H11B255SD is supplied in standard packaging. The H11B1SR2M is supplied in Tape & Reel (TR) format, which is standard for active production components and provides cost and handling advantages for high-volume applications.