MOC3082FM Optoisolator Equivalent & Substitute Parts

Part Overview

The MOC3082FM is a 7.5kV isolation optoisolator with triac output manufactured by onsemi. This component features a zero-crossing circuit, single channel configuration, and surface mount 6-SMD packaging. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

MOC3082FM

onsemiIn Stock: 1231MOC3082FM Datasheet

Current PartRFQ

MOC3082SM

Fairchild SemiconductorIn Stock: 1522MOC3082SM Datasheet

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EL3081

Everlight Electronics Co LtdIn Stock: 24397EL3081 Datasheet

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EL3082

Everlight Electronics Co LtdIn Stock: 1642EL3082 Datasheet

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EL3083

Everlight Electronics Co LtdIn Stock: 94310EL3083 Datasheet

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Q3082

QT Brightek (QTB)In Stock: 921Q3082 Datasheet

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Q3083

QT Brightek (QTB)In Stock: 835Q3083 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the MOC3082FM is determined by the following critical parameters:

Primary Substitution Criteria:

• Output Type: Triac
• Zero Crossing Circuit: Yes
• Number of Channels: 1
• Voltage - Off State: 800 V
• Current - DC Forward (If) (Max): 60 mA
• Mounting Type: Surface Mount or Through Hole (with design accommodation)
• Package compatibility: 6-SMD or 6-DIP

Isolation Voltage Consideration: The MOC3082FM specifies 7500Vpk isolation. Substitute parts with lower isolation ratings (4170Vrms to 5000Vrms) remain functionally compatible for applications where the lower isolation voltage meets system requirements.

Current Trigger Consideration: The MOC3082FM requires maximum 10mA LED trigger current. Substitute parts with equal or lower trigger current requirements (5mA to 15mA) are acceptable.

Substitute parts are grouped into two categories:

1. Surface Mount (SMD) Substitutes: MOC3082SM (Fairchild Semiconductor) - maintains original mounting type
2. Through Hole (DIP) Substitutes: EL3081, EL3082, EL3083 (Everlight Electronics), Q3082, Q3083 (QT Brightek) - requires PCB redesign for package conversion

Parameter Comparison

Engineering Selection Recommendations

MOC3082SM (Fairchild Semiconductor) is the primary direct substitute for surface mount applications. It maintains the 6-SMD, Gull Wing package format, eliminating PCB redesign requirements. The part is active and UL-approved. The isolation voltage is lower (4170Vrms vs. 7500Vpk), which is acceptable for applications where system isolation requirements do not exceed 4170Vrms.

EL3081, EL3082, EL3083 (Everlight Electronics) and Q3082, Q3083 (QT Brightek) are suitable for through-hole PCB designs. These parts require package conversion from SMD to DIP and PCB layout modification. All Everlight parts carry comprehensive agency approvals (CSA, DEMKO, FIMKO, NEMKO, SEMKO, UL) and are ROHS3 compliant. QT Brightek parts carry UR and VDE approvals and are ROHS3 compliant.

EL3083 and Q3083 feature the lowest LED trigger current requirement (5mA maximum), offering reduced input drive requirements compared to the MOC3082FM (10mA maximum).

EL3081 and Q3082 specify 15mA and 10mA LED trigger current respectively, matching or exceeding the MOC3082FM specification.

All substitute parts maintain the critical functional parameters: triac output, zero-crossing circuit, single channel, 800V off-state voltage, and 60mA maximum forward current.

Frequently Asked Questions (FAQ)

Q: Can MOC3082SM directly replace MOC3082FM without PCB modification?

A: Yes. MOC3082SM uses identical 6-SMD, Gull Wing packaging and pinout compatibility with MOC3082FM. No PCB layout changes are required. The lower isolation voltage (4170Vrms vs. 7500Vpk) must be verified against system isolation requirements.

Q: What is the difference between the Everlight EL3081, EL3082, and EL3083 parts?

A: All three are 6-DIP through-hole optoisolators with identical isolation voltage (5000Vrms), off-state voltage (800V), and operating temperature range (-55°C to 100°C). The primary difference is LED trigger current: EL3081 requires 15mA maximum, EL3082 requires 10mA maximum, and EL3083 requires 5mA maximum. Selection depends on input drive circuit capability.

Q: Can I use a through-hole DIP substitute in place of the surface mount MOC3082FM?

A: Through-hole substitutes (EL3081, EL3082, EL3083, Q3082, Q3083) require PCB redesign to accommodate 6-DIP footprint and through-hole mounting. This is not a direct drop-in replacement and involves design modification.

Q: What isolation voltage should I use for substitute selection?

A: The MOC3082FM specifies 7500Vpk isolation. Substitute parts with lower isolation ratings (4170Vrms to 5000Vrms) are acceptable only if your application isolation requirements do not exceed the substitute part's rating. Verify system isolation voltage specifications before selection.

Q: Are all substitute parts RoHS compliant?

A: Everlight (EL3081, EL3082, EL3083) and QT Brightek (Q3082, Q3083) parts are ROHS3 compliant. MOC3082SM compliance status is not specified in available data.

Q: Which substitute part has the best agency approvals?

A: Everlight parts (EL3081, EL3082, EL3083) carry the most comprehensive approvals: CSA, DEMKO, FIMKO, NEMKO, SEMKO, and UL. QT Brightek parts (Q3082, Q3083) carry UR and VDE approvals. MOC3082SM carries UL approval.

Q: What is the difference between Vpk and Vrms isolation voltage specifications?

A: Vpk (peak voltage) and Vrms (RMS voltage) are different measurement standards for isolation voltage. The MOC3082FM specifies 7500Vpk. Substitute parts specify isolation in Vrms. Direct numerical comparison requires conversion; however, for substitution purposes, verify that the substitute part's isolation rating meets or exceeds your system requirements.