MOC3083FM Optoisolator Equivalent & Substitute Parts

Part Overview

The MOC3083FM is a 7.5kV isolation optoisolator with triac output and zero-crossing circuit, manufactured by onsemi in 6-SMD surface mount packaging. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The MOC3083FM serves applications requiring galvanic isolation with triac-based switching control in AC power circuits.

Key Parameters

Parameter	MOC3083FM
Manufacturer	onsemi
Category	Optoisolators
Output Type	Triac
Zero Crossing Circuit	Yes
Number of Channels	1
Voltage - Isolation	7500Vpk
Voltage - Off State	800 V
Current - LED Trigger (Ift) (Max)	5mA
Current - Hold (Ih)	500µA (Typ)
Current - DC Forward (If) (Max)	60 mA
Mounting Type	Surface Mount
Package / Case	6-SMD, Gull Wing
Product Status	Obsolete
Base Product Number	MOC308
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution for the MOC3083FM is determined by the following critical parameters:

Primary Compatibility Criteria:

Output Type: Triac
Zero Crossing Circuit: Yes
Number of Channels: 1
Voltage - Off State: 800 V
Current - LED Trigger (Ift) (Max): 5mA
Current - DC Forward (If) (Max): 60 mA
Base Product Number: MOC308 or equivalent series

Substitution Categories:

Category 1: Direct SMD Equivalent MOC3083SM (Fairchild Semiconductor) maintains surface mount packaging (6-SMD, Gull Wing) with active product status. Isolation voltage differs (4170Vrms vs. 7500Vpk), requiring application-level voltage verification.

Category 2: Through-Hole Alternatives EL3081, EL3082, EL3083 (Everlight Electronics), and Q3082, Q3083 (QT Brightek) provide through-hole 6-DIP packaging with 5000Vrms isolation voltage. These require PCB redesign for mounting compatibility but maintain core triac output functionality with zero-crossing detection.

Parameter Comparison

Parameter	MOC3083FM	MOC3083SM	EL3081	EL3082	EL3083	Q3082	Q3083
Manufacturer	onsemi	Fairchild Semiconductor	Everlight Electronics	Everlight Electronics	Everlight Electronics	QT Brightek	QT Brightek
Output Type	Triac	Triac	Triac	Triac	Triac	Triac	Triac
Zero Crossing Circuit	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Number of Channels	1	1	1	1	1	1	1
Voltage - Isolation	7500Vpk	4170Vrms	5000Vrms	5000Vrms	5000Vrms	5000Vrms	5000Vrms
Voltage - Off State	800 V	800 V	800 V	800 V	800 V	800 V	800 V
Static dV/dt (Min)	—	600V/µs	600V/µs	600V/µs	600V/µs	600V/µs	600V/µs
Current - LED Trigger (Ift) (Max)	5mA	5mA	15mA	10mA	5mA	10mA	5mA
Current - Hold (Ih)	500µA (Typ)	500µA (Typ)	280µA (Typ)	280µA (Typ)	280µA (Typ)	280µA (Typ)	280µA (Typ)
Current - DC Forward (If) (Max)	60 mA	60 mA	60 mA	60 mA	60 mA	60 mA	60 mA
Voltage - Forward (Vf) (Typ)	—	1.3V	1.5V (Max)	1.5V (Max)	1.5V (Max)	1.5V (Max)	1.5V (Max)
Operating Temperature	—	-40°C ~ 85°C	-55°C ~ 100°C	-55°C ~ 100°C	-55°C ~ 100°C	-55°C ~ 100°C	-55°C ~ 100°C
Mounting Type	Surface Mount	Surface Mount	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	6-SMD, Gull Wing	6-SMD, Gull Wing	6-DIP (0.300", 7.62mm)	6-DIP (0.300", 7.62mm)	6-DIP (0.300", 7.62mm)	6-DIP (0.300", 7.62mm)	6-DIP (0.300", 7.62mm)
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
RoHS Status	—	—	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	—	UL	CSA, DEMKO, FIMKO, NEMKO, SEMKO, UL	CSA, DEMKO, FIMKO, NEMKO, SEMKO, UL	CSA, DEMKO, FIMKO, NEMKO, SEMKO, UL	UR, VDE	UR, VDE

Engineering Selection Recommendations

For Surface Mount Applications (No PCB Redesign): MOC3083SM is the only active substitute maintaining 6-SMD, Gull Wing packaging. This part is active and carries UL approval. The isolation voltage specification (4170Vrms) is lower than the MOC3083FM (7500Vpk). Selection requires verification that application voltage requirements do not exceed 4170Vrms RMS equivalent.

For Through-Hole Applications (PCB Redesign Required): EL3083 and Q3083 both specify 5mA maximum LED trigger current, matching the MOC3083FM exactly. Both are active products with comprehensive safety certifications (Everlight: CSA, DEMKO, FIMKO, NEMKO, SEMKO, UL; QT Brightek: UR, VDE). EL3083 offers higher inventory availability (94,200 units) and extended temperature range (-55°C to 100°C). Q3083 provides alternative sourcing with active product status and RoHS3 compliance.

EL3081 and Q3082 specify higher LED trigger current (15mA and 10mA respectively), requiring driver circuit adjustment but offering additional design margin.

Compliance Considerations: All substitute parts maintain 800V off-state voltage and 60mA maximum forward current. Everlight and QT Brightek parts provide RoHS3 compliance; MOC3083SM compliance status is not specified. All parts carry recognized safety agency approvals suitable for AC power control applications.

Frequently Asked Questions (FAQ)

Q: Can MOC3083SM replace MOC3083FM without PCB changes? A: Yes, MOC3083SM uses identical 6-SMD, Gull Wing packaging. However, isolation voltage differs (4170Vrms vs. 7500Vpk). Verify application voltage requirements before substitution.

Q: What is the key difference between EL3083 and Q3083? A: Both specify 5mA LED trigger current and 5000Vrms isolation. EL3083 offers higher inventory (94,200 units) and extended temperature range (-55°C to 100°C). Q3083 provides alternative sourcing with UR and VDE certifications. Electrical performance is equivalent.

Q: Do through-hole substitutes require circuit redesign? A: Yes. EL3081, EL3082, EL3083, Q3082, and Q3083 use 6-DIP through-hole packaging versus MOC3083FM's surface mount format. PCB layout and footprint redesign is required.

Q: Which substitute has the lowest LED trigger current requirement? A: MOC3083SM, EL3083, and Q3083 all specify 5mA maximum LED trigger current, matching MOC3083FM. EL3081 and Q3082 require 15mA and 10mA respectively, necessitating higher driver current capability.

Q: Are all substitutes RoHS compliant? A: Everlight (EL3081, EL3082, EL3083) and QT Brightek (Q3082, Q3083) parts are ROHS3 compliant. MOC3083SM RoHS status is not specified in available data.

Q: What certifications apply to these optoisolators? A: Everlight parts carry CSA, DEMKO, FIMKO, NEMKO, SEMKO, and UL approvals. QT Brightek parts carry UR and VDE approvals. MOC3083SM carries UL approval. All certifications are suitable for AC power switching applications.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message