Is there a pin-compatible replacement for MOC3021SR2M?

Yes, MOC3041SR2M and MOC3061SR2M share the same 6-SMD package and pinout. However, they are functionally different (zero-crossing vs. random-phase), which requires careful application review before use.

What risks should I check before replacing MOC3021SR2M?

The main risk is the functional difference. Using a zero-crossing driver in an application designed for a random-phase driver can lead to malfunction, especially in phase control (dimming) or with inductive loads (motors). Always verify circuit requirements.

MOC3021SR2M Alternatives, Datasheet & Cross Reference | onsemi

The onsemi MOC3021SR2M is a random-phase triac driver optocoupler in a 6-SMD package, used for AC load control. Finding a direct replacement requires matching the random-phase functionality, which is critical for dimming and inductive loads.

AI replacement insight

Electrical riskhigh

Zero-crossing vs random-phase is a critical functional difference.

Package risklow

SMD candidates match the target's form factor.

Can it be replaced directly?

No direct, random-phase, pin-compatible replacement was identified. All similar candidates are zero-crossing drivers, which is a critical functional difference.

Best replacement path

Use MOC3041SR2M for applications where a zero-crossing driver is acceptable, as it matches the package and voltage rating.

Main risk

Functional mismatch: replacing a random-phase driver with a zero-crossing driver can cause circuit failure in phase control or inductive load applications.

Recommended alternatives

Form-fit compatible but functionally different; it is a zero-crossing driver, not random-phase.

View details

Alternative comparison matrix

Feature / factor	MOC3021SR2M	MOC3041SR2M	MOC3061SR2M	Compatibility / risk
Package	6-SMD, Gull Wing	6-SMD, Gull Wing	6-SMD, Gull Wing	6-SMD, Gull Wing — Package and pin count match.; MOC3061SR2M: Package and pin count match.
Application	Triac, Random-Phase	Triac, Zero-Crossing	Triac, Zero-Crossing	Triac, Zero-Crossing — Candidate is zero-crossing, target is random-phase. Not for phase control.; MOC3061SR2M: Candidate is zero-crossing, target is random-phase. Not for phase control.
Voltage	400V	400V	600V	400V / 600V — Off-state voltage matches.; MOC3061SR2M: Higher off-state voltage provides more margin.
Current	15mA	15mA	15mA	15mA — LED trigger current matches.; MOC3061SR2M: LED trigger current matches.

Application & sourcing insights

Questions & answers

While no direct random-phase replacements were found, MOC3041SR2M and MOC3061SR2M are form-fit compatible zero-crossing alternatives. They are suitable for simple on/off control of resistive loads but not for phase control or inductive loads.