MOC8204SD Equivalent & Substitute Parts

Part Overview

The MOC8204SD is an optoisolator transistor with base output manufactured by onsemi, designed for high-voltage isolation applications requiring 5300Vrms isolation rating. This component features a single channel with transistor output and base connection, suitable for DC input applications. The product is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

MOC8204SD

onsemiIn Stock: 864MOC8204SD Datasheet

Current PartRFQ

MOC8204SR2M

Fairchild SemiconductorIn Stock: 4264MOC8204SR2M Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The MOC8204SR2M qualifies as a direct substitute based on the following alignment of critical electrical and mechanical parameters:

Matching Parameters:

• Single channel configuration
• Transistor with base output topology
• 400V maximum output voltage
• 400mV maximum Vce saturation
• 20% minimum current transfer ratio @ 10mA
• 5µs turn-on and turn-off time
• DC input type
• 6-SMD, Gull Wing package
• Surface mount mounting type
• EAR99 ECCN classification
• 8541.49.8000 HTSUS code

Allowable Variations:

• Isolation voltage: MOC8204SR2M provides 4170Vrms versus MOC8204SD's 5300Vrms. The substitute meets minimum isolation requirements for applications not requiring the full 5300Vrms specification.
• Output current: MOC8204SR2M supports 100mA versus MOC8204SD's 2mA, providing enhanced current capability.
• Operating temperature: MOC8204SR2M operates -40°C ~ 100°C versus MOC8204SD's -55°C ~ 100°C. The substitute covers standard industrial temperature ranges.
• Forward voltage: MOC8204SR2M specifies 1.15V versus MOC8204SD's 1.2V, representing a minor reduction in input-side voltage drop.

Parameter Comparison

Engineering Selection Recommendations

The MOC8204SR2M is suitable as a substitute for the obsolete MOC8204SD in applications where the following conditions are met:

1. Isolation Voltage Requirement: Applications requiring isolation voltage of 4170Vrms or less can utilize the MOC8204SR2M. Systems designed for the full 5300Vrms isolation of the original part require verification that 4170Vrms meets the application's safety and regulatory margins.

2. Output Current Capacity: The MOC8204SR2M's 100mA output current capability exceeds the MOC8204SD's 2mA specification, providing design flexibility for higher-current switching applications.

3. Temperature Operating Range: The MOC8204SR2M operates within -40°C ~ 100°C. Applications requiring operation below -40°C must retain the original MOC8204SD or identify alternative solutions.

4. Product Availability and Support: The MOC8204SR2M maintains active product status with established supply channels, whereas the MOC8204SD is obsolete. Transition to the substitute ensures long-term component availability and manufacturer support.

5. Compliance and Certification: Both parts share identical ECCN (EAR99) and HTSUS (8541.49.8000) classifications, ensuring equivalent regulatory treatment in export and procurement contexts.

Frequently Asked Questions (FAQ)

Q: Can MOC8204SR2M directly replace MOC8204SD in existing designs?

A: Direct replacement is possible when the application's isolation voltage requirement does not exceed 4170Vrms and the operating temperature range remains within -40°C ~ 100°C. The identical package (6-SMD, Gull Wing), pin configuration, and output characteristics (400V maximum, 400mV Vce saturation) support pin-for-pin substitution. Verify isolation voltage margins in your specific application before implementation.

Q: What is the significance of the isolation voltage difference?

A: The MOC8204SD provides 5300Vrms isolation, while MOC8204SR2M provides 4170Vrms. This difference represents the maximum voltage that can be safely isolated between input and output circuits. Applications designed for 5300Vrms isolation must confirm that 4170Vrms meets safety standards and regulatory requirements for the intended use case.

Q: Are there differences in switching speed between these parts?

A: No. Both parts specify identical turn-on and turn-off times of 5µs, ensuring equivalent switching performance in DC input applications.

Q: How does the increased output current affect circuit design?

A: The MOC8204SR2M supports 100mA output current compared to the MOC8204SD's 2mA. This higher capability allows the substitute to drive higher-impedance loads or multiple downstream components without additional buffering stages. Existing designs using the MOC8204SD's 2mA specification will operate within the MOC8204SR2M's capability envelope.

Q: What packaging considerations apply to this substitution?

A: Both parts use identical 6-SMD, Gull Wing surface mount packaging. PCB footprints, reflow profiles, and assembly processes remain unchanged. No mechanical redesign is required.

Q: Are there supply chain advantages to using MOC8204SR2M?

A: Yes. The MOC8204SR2M maintains active product status with established inventory and manufacturer support, whereas the MOC8204SD is obsolete. Transitioning to the substitute ensures reliable long-term availability and reduces supply chain risk.