MOC3021M Equivalent & Substitute Parts

Part Overview

The MOC3021M is an optoisolator with triac output manufactured by Lite-On Inc., designed for applications requiring galvanic isolation up to 5000Vrms. This component integrates an LED input stage with a triac output stage in a 6-DIP package, operating across the industrial temperature range of -40°C to 100°C. The part is active in production and widely stocked with 125,200 units available. Substitute parts are necessary when addressing supply constraints, regional availability, or specific packaging requirements while maintaining functional equivalence within defined electrical parameters.

Substiute Parts

MOC3021M

Lite-On Inc.In Stock: 125258MOC3021M Datasheet

Current PartRFQ

MOC3021M

Fairchild SemiconductorIn Stock: 125239MOC3021M Datasheet

DirectRFQ

MOC3020TVM

onsemiIn Stock: 2092MOC3020TVM Datasheet

MFR RecommendedRFQ

MOC3021TVM

Fairchild SemiconductorIn Stock: 12939MOC3021TVM Datasheet

MFR RecommendedRFQ

MOC3022TVM

onsemiIn Stock: 1397MOC3022TVM Datasheet

MFR RecommendedRFQ

MOC3023TVM

onsemiIn Stock: 6654MOC3023TVM Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MOC3021M is determined by the following critical parameters:

Primary Substitution Criteria:

• Output Type: Triac (mandatory)
• Number of Channels: 1 (mandatory)
• Mounting Type: Through Hole (mandatory)
• Package / Case: 6-DIP configuration (mandatory)
• Voltage - Isolation: 5000Vrms or higher (mandatory)
• Voltage - Off State: 400 V (mandatory)
• Operating Temperature Range: Must support -40°C minimum and 100°C maximum (mandatory)

Secondary Compatibility Parameters:

• Current - LED Trigger (Ift): 15mA maximum or lower
• Current - Hold (Ih): 250µA typical or lower
• Voltage - Forward (Vf): 1.15V typical
• Current - DC Forward (If): 50 mA maximum or higher

The substitute parts listed below meet the mandatory criteria. Variations in secondary parameters indicate different triggering sensitivities and forward current ratings, which may affect circuit design but do not prevent functional substitution when the application tolerates these differences.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalents (Highest Compatibility):

MOC3021M (Fairchild Semiconductor) and MOC3021M (Lite-On Inc.) are functionally identical across all specified parameters. Both maintain 5000Vrms isolation voltage, identical trigger current specifications (15mA maximum), and full operating temperature range to 100°C. Selection between these two is based on availability and regional supply chain considerations. Both are ROHS3 compliant and carry equivalent regulatory approvals (CQC, CSA, TUV, UL, VDE).

Conditional Substitutes (Parameter Deviations):

MOC3020TVM, MOC3021TVM, MOC3022TVM, and MOC3023TVM are functionally substitutable with documented parameter variations:

• All four parts reduce isolation voltage to 4170Vrms, which is acceptable only in applications where 5000Vrms isolation is not a design requirement.
• All four parts limit operating temperature to 85°C maximum, which excludes use in applications requiring the full -40°C to 100°C range.
• All four parts feature 6-DIP packages with 0.400" (10.16mm) pitch, requiring PCB layout verification against the original 0.300" (7.62mm) pitch design.
• MOC3020TVM specifies 30mA maximum trigger current, requiring higher LED drive current than the original design.
• MOC3022TVM and MOC3023TVM specify lower trigger currents (10mA and 5mA respectively), enabling reduced LED drive requirements.

All substitute parts maintain active product status and carry appropriate regulatory approvals (IEC/EN/DIN, UL). ROHS3 compliance is confirmed for onsemi variants.

Frequently Asked Questions (FAQ)

Q: Can MOC3020TVM, MOC3021TVM, MOC3022TVM, or MOC3023TVM be used as direct replacements for MOC3021M?

A: These parts are functionally substitutable only when the application does not require 5000Vrms isolation voltage and operates within the reduced temperature range of -40°C to 85°C. The 6-DIP package pitch difference (0.400" versus 0.300") requires PCB layout verification. Trigger current specifications vary across these parts and must be evaluated against LED drive circuit design.

Q: What is the primary difference between MOC3021M from Lite-On and MOC3021M from Fairchild Semiconductor?

A: Both parts are electrically and mechanically identical across all specified parameters. The difference is manufacturer origin. Selection is based on supply availability and regional sourcing preferences.

Q: Why do MOC3020TVM, MOC3021TVM, MOC3022TVM, and MOC3023TVM have lower isolation voltage ratings?

A: These parts are from the MOC302x series with different internal design specifications. The 4170Vrms rating is a design characteristic of these variants. Applications requiring 5000Vrms isolation must use MOC3021M or equivalent 5000Vrms-rated parts.

Q: Can I use MOC3023TVM in place of MOC3021M if my circuit only needs 4170Vrms isolation?

A: Yes, provided the application operates within -40°C to 85°C and the PCB layout accommodates the 0.400" (10.16mm) DIP pitch. MOC3023TVM specifies 5mA maximum trigger current, which is lower than MOC3021M's 15mA specification. Verify that the LED drive circuit can supply the required current for reliable triggering.

Q: Are all substitute parts ROHS3 compliant?

A: ROHS3 compliance is confirmed for MOC3021M (Lite-On), MOC3020TVM, MOC3022TVM, and MOC3023TVM. Fairchild Semiconductor variants do not specify ROHS3 status in the provided data.

Q: What is the significance of the 6-DIP package pitch difference?

A: The original MOC3021M uses 0.300" (7.62mm) pitch, while substitute parts use 0.400" (10.16mm) pitch. This affects PCB hole spacing and component placement. Designs must be verified for mechanical compatibility before substitution.