MOC3042FVM Equivalent & Substitute Parts

Part Overview

The MOC3042FVM is a surface mount optoisolator with triac output, designed for high-voltage isolation applications. Manufactured by onsemi, this component provides 7500Vpk isolation voltage with a single triac channel and integrated zero-crossing detection circuit. The part is currently classified as obsolete, making identification of compatible substitutes essential for ongoing system support and new design implementations. The MOC3042FVM operates in 6-SMD gull wing packaging and is suitable for applications requiring reliable galvanic isolation in AC switching circuits.

Substiute Parts

MOC3042FVM

onsemiIn Stock: 1154MOC3042FVM Datasheet

Current PartRFQ

MOC3042SVM

onsemiIn Stock: 1924MOC3042SVM Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MOC3042FVM is determined by alignment across the following critical parameters:

Mandatory Compatibility Parameters:

• Output Type: Triac configuration required
• Number of Channels: Single channel operation
• Zero Crossing Circuit: Integrated zero-crossing detection
• Mounting Type: Surface mount technology
• Package / Case: 6-SMD, Gull Wing form factor
• Current - LED Trigger (Ift) (Max): 10mA maximum
• Current - Hold (Ih) (Typ): 400µA typical
• Current - DC Forward (If) (Max): 60 mA maximum
• Voltage - Off State: 400 V rating

Isolation Voltage Consideration: The MOC3042FVM specifies 7500Vpk isolation. Substitute parts must maintain isolation voltage ratings that satisfy the original design requirements. Lower isolation voltage ratings represent a functional constraint that must be evaluated against specific application needs.

The MOC3042SVM qualifies as a substitute based on matching all mandatory compatibility parameters. While the MOC3042SVM provides 4170Vrms isolation (lower than the original 7500Vpk), it maintains the same triac output architecture, channel count, zero-crossing functionality, and electrical trigger characteristics.

Parameter Comparison

Engineering Selection Recommendations

The MOC3042SVM is the identified substitute for the obsolete MOC3042FVM. Selection between these parts is determined by isolation voltage requirements:

MOC3042FVM (Obsolete): Provides 7500Vpk isolation voltage. This part is no longer in active production. Existing inventory may be available through authorized distributors, but long-term supply cannot be assured.

MOC3042SVM (Active): Provides 4170Vrms isolation voltage with active product status and ongoing manufacturing support. This part carries ROHS3 compliance and holds IEC/EN/DIN and UL approvals, meeting current regulatory standards. The MOC3042SVM is recommended for new designs and ongoing production where isolation voltage requirements do not exceed 4170Vrms.

The decision to substitute MOC3042FVM with MOC3042SVM depends on whether the application circuit design can operate within the lower isolation voltage specification of 4170Vrms. If the original design requires 7500Vpk isolation voltage, alternative optoisolator families outside the MOC304 base product series must be evaluated.

Frequently Asked Questions (FAQ)

Q: Can MOC3042SVM directly replace MOC3042FVM in existing designs?

A: Direct replacement is possible only if the application circuit operates within the 4170Vrms isolation voltage specification. All other electrical and mechanical parameters are identical. PCB layout and component placement remain unchanged due to matching 6-SMD gull wing packaging.

Q: What is the difference between 7500Vpk and 4170Vrms isolation ratings?

A: These represent different measurement standards for isolation voltage. The MOC3042FVM specifies peak voltage (Vpk), while the MOC3042SVM specifies RMS voltage (Vrms). The lower numerical value of the MOC3042SVM reflects a reduced isolation capability. Applications requiring the full 7500Vpk isolation margin cannot use the MOC3042SVM as a substitute.

Q: Why is MOC3042FVM classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The MOC3042SVM represents the active product line continuation within the MOC304 family, offering improved compliance certifications and ongoing supply availability.

Q: Are there packaging differences between these parts?

A: Both parts use identical 6-SMD gull wing surface mount packaging. No PCB redesign or reflow profile adjustment is required for physical substitution.

Q: What compliance certifications apply to each part?

A: The MOC3042FVM does not list specific approval agencies. The MOC3042SVM holds IEC/EN/DIN and UL approvals and is ROHS3 compliant, meeting current regulatory requirements for industrial and consumer applications.

Q: Is the zero-crossing circuit function identical in both parts?

A: Yes. Both the MOC3042FVM and MOC3042SVM include integrated zero-crossing detection circuits. This feature enables synchronized triac switching at AC line voltage zero crossings, reducing EMI and improving system reliability.