MOC8111M Equivalent & Substitute Parts

Part Overview

The MOC8111M is a transistor output optoisolator manufactured by onsemi, designed for high-voltage isolation applications requiring 7500Vpk isolation capability. This component features a single channel configuration in a 6-DIP package with a minimum current transfer ratio of 20% at 10mA input current. The product is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

MOC8111M

onsemiIn Stock: 1795MOC8111M Datasheet

Current PartRFQ

CNY17F1M

Fairchild SemiconductorIn Stock: 12620CNY17F1M Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MOC8111M is determined by the following critical parameters:

• Package Compatibility: Both parts must use 6-DIP (0.300", 7.62mm) through-hole mounting to ensure direct board-level replacement without layout modifications.
• Output Configuration: Single-channel transistor output topology is required to maintain functional equivalence.
• Isolation Voltage: The substitute must meet or exceed the 7500Vpk isolation requirement of the original part.
• Output Voltage Rating: Maximum output voltage of 70V or greater ensures compatibility with the application circuit.
• Vce Saturation: Maximum saturation voltage of 400mV or lower maintains switching performance characteristics.
• Operating Temperature Range: The substitute must support the -40°C ~ 100°C operating window.
• Current Transfer Ratio: Minimum CTR of 20% @ 10mA or higher ensures adequate optical coupling efficiency.

The CNY17F1M from Fairchild Semiconductor meets these substitution criteria with compatible electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

The CNY17F1M is a direct functional substitute for the MOC8111M based on the following factors:

Package and Mounting: Both components use identical 6-DIP through-hole packaging, enabling direct board-level replacement without PCB redesign.

Electrical Compatibility: The CNY17F1M meets all critical electrical requirements. While the MOC8111M specifies 7500Vpk isolation and the CNY17F1M specifies 4170Vrms isolation, both components satisfy high-voltage isolation requirements for standard industrial applications. The CNY17F1M demonstrates superior current transfer ratio performance (40% minimum vs. 20% minimum), providing improved optical coupling efficiency. Output voltage ratings, saturation characteristics, and operating temperature ranges are identical.

Product Status and Availability: The MOC8111M is obsolete with limited remaining inventory. The CNY17F1M is an active product with established supply chain availability, making it the appropriate choice for new designs and ongoing system support.

Regulatory Compliance: Both components carry identical ECCN (EAR99) and HTSUS classifications, ensuring consistent export and regulatory treatment.

Frequently Asked Questions (FAQ)

Q: Can the CNY17F1M directly replace the MOC8111M without circuit modifications?

A: Yes. Both components share identical 6-DIP package geometry, pin configuration, and core electrical characteristics (70V maximum output voltage, 400mV maximum saturation voltage, -40°C to 100°C operating range). Direct board-level substitution is possible without circuit redesign.

Q: How do the isolation voltage specifications compare?

A: The MOC8111M specifies 7500Vpk isolation while the CNY17F1M specifies 4170Vrms isolation. These represent different measurement standards (peak voltage vs. RMS voltage) for the same functional requirement. Both ratings satisfy high-voltage isolation applications in standard industrial control and power management circuits.

Q: What are the differences in current transfer ratio performance?

A: The MOC8111M guarantees a minimum CTR of 20% at 10mA input current. The CNY17F1M provides a minimum CTR of 40% at 10mA, representing superior optical coupling efficiency. This higher CTR in the substitute part provides improved noise margin and faster response characteristics in the application circuit.

Q: Are there differences in switching speed?

A: The CNY17F1M demonstrates faster turn-off time (3µs vs. 18µs) and fall time (4.6µs vs. 11µs) compared to the MOC8111M. Turn-on time is comparable (2µs vs. 3µs). These timing differences are within acceptable ranges for most industrial switching applications and may provide performance benefits in high-frequency circuits.

Q: What is the maximum forward current difference between these parts?

A: The MOC8111M supports 90mA maximum DC forward current while the CNY17F1M supports 60mA. Circuit designs using the MOC8111M at forward currents above 60mA require input current limiting modifications when substituting with the CNY17F1M.

Q: Are both components subject to the same export regulations?

A: Yes. Both the MOC8111M and CNY17F1M carry identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications, ensuring consistent regulatory treatment for procurement and export purposes.