MOC81043S Equivalent & Substitute Parts

Part Overview

The MOC81043S is a 6-SMD surface mount optoisolator with transistor output manufactured by onsemi. It provides 5300Vrms isolation voltage and is designed for single-channel DC input applications with transistor output capability. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

MOC81043S

onsemiIn Stock: 731MOC81043S Datasheet

Current PartRFQ

CNY17F4SM

Fairchild SemiconductorIn Stock: 2269CNY17F4SM Datasheet

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CNY17F4SVM

Fairchild SemiconductorIn Stock: 2818CNY17F4SVM Datasheet

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MOC8104-X019T

Vishay Semiconductor Opto DivisionIn Stock: 3877MOC8104-X019T Datasheet

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MOC8104SM

Isocom Components 2004 LTDIn Stock: 1153MOC8104SM Datasheet

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MOC8104SMT&R

Isocom Components 2004 LTDIn Stock: 871MOC8104SMT&R Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MOC81043S optoisolator is determined by the following critical parameters:

Primary Substitution Criteria:

• Single channel configuration
• Transistor output topology
• 6-SMD surface mount package with gull wing leads
• Isolation voltage rating (minimum 5300Vrms preferred for direct replacement)
• Current transfer ratio range (160% minimum @ 10mA)
• Maximum output voltage (30V or higher)
• Maximum output current (50mA or higher)
• Vce saturation (400mV or lower)
• Operating temperature range (-55°C to 100°C or compatible subset)

Substitution Groups:

Group 1 - Direct Electrical Equivalents (5300Vrms Isolation): MOC8104-X019T and MOC8104SM/MOC8104SMT&R maintain the same 5300Vrms isolation voltage as the MOC81043S, providing direct functional replacement with identical electrical performance specifications.

Group 2 - Functional Equivalents (Lower Isolation Voltage): CNY17F4SM and CNY17F4SVM operate at 4170Vrms isolation voltage, which is lower than the MOC81043S. These parts are functionally compatible for applications where the reduced isolation voltage is acceptable, maintaining equivalent transistor output characteristics and package form factor.

Parameter Comparison

Engineering Selection Recommendations

MOC8104-X019T (Vishay Semiconductor Opto Division) is the primary recommended substitute. It maintains identical isolation voltage (5300Vrms), current transfer ratio specifications (160%-256% @ 10mA), and output voltage/current ratings. The part is active in production with ROHS3 compliance and REACH unaffected status. Packaging is available in Tape & Reel format.

MOC8104SM and MOC8104SMT&R (Isocom Components 2004 LTD) provide equivalent electrical performance with 5300Vrms isolation voltage and identical output specifications. Both variants are active products with ROHS3 compliance. MOC8104SM is supplied in Tube packaging, while MOC8104SMT&R is supplied in Tape & Reel format. Note that current transfer ratio specifications are not provided for these variants.

CNY17F4SM and CNY17F4SVM (Fairchild Semiconductor) are functional substitutes with reduced isolation voltage (4170Vrms). These parts are suitable for applications where lower isolation voltage is acceptable. Both maintain 160% minimum current transfer ratio and identical output current/voltage ratings. Operating temperature range is -40°C to 100°C, which is narrower than the MOC81043S. CNY17F4SM is supplied in Bulk packaging, while CNY17F4SVM is also supplied in Bulk packaging.

Frequently Asked Questions (FAQ)

Q: Can MOC8104-X019T directly replace MOC81043S in all applications?

A: MOC8104-X019T is electrically equivalent to MOC81043S with matching 5300Vrms isolation voltage, current transfer ratio range, and output specifications. Both use identical 6-SMD gull wing packaging. Direct substitution is supported for applications requiring these specifications.

Q: What is the difference between MOC8104SM and MOC8104SMT&R?

A: Both parts are manufactured by Isocom Components 2004 LTD with identical electrical specifications. The primary difference is packaging: MOC8104SM is supplied in Tube format, while MOC8104SMT&R is supplied in Tape & Reel format. Selection depends on procurement and assembly requirements.

Q: Can CNY17F4SM be used instead of MOC81043S?

A: CNY17F4SM is functionally compatible but operates at 4170Vrms isolation voltage compared to MOC81043S at 5300Vrms. It maintains equivalent transistor output characteristics and 6-SMD package form factor. Substitution is valid only for applications where the reduced isolation voltage meets design requirements. Operating temperature range is also narrower (-40°C to 100°C versus -55°C to 100°C).

Q: What are the key parameters that determine substitution compatibility?

A: Substitution compatibility is determined by: single channel configuration, transistor output topology, 6-SMD surface mount package, isolation voltage rating, current transfer ratio (minimum 160% @ 10mA), maximum output voltage (30V or higher), maximum output current (50mA or higher), and Vce saturation (400mV or lower).

Q: Are all substitute parts currently in production?

A: MOC81043S is obsolete. All listed substitutes (MOC8104-X019T, MOC8104SM, MOC8104SMT&R, CNY17F4SM, CNY17F4SVM) are active products in current production.

Q: What compliance certifications apply to these parts?

A: MOC8104-X019T, MOC8104SM, and MOC8104SMT&R are ROHS3 compliant and REACH unaffected. Compliance information for CNY17F4SM and CNY17F4SVM is not provided in the available specifications.