MM3Z39VST1G Equivalent & Substitute Parts

Part Overview

The MM3Z39VST1G is a Zener diode rated at 39 V nominal voltage with 300 mW maximum power dissipation in a surface mount SOD-323 package. This component is manufactured by onsemi and is currently classified as obsolete. Due to its obsolete status, equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for new production runs and field replacements. Substitute parts must maintain electrical compatibility across critical parameters including Zener voltage, power rating, and thermal operating range while accommodating packaging and tolerance variations.

Substiute Parts

MM3Z39VST1G

onsemiIn Stock: 721MM3Z39VST1G Datasheet

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MM3Z39VT1G

onsemiIn Stock: 44419MM3Z39VT1G Datasheet

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DDZ39FS-7

Diodes IncorporatedIn Stock: 824DDZ39FS-7 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM3Z39VST1G is determined by strict alignment of the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

• Zener voltage (Nom): 39 V (exact match required)
• Package / Case: SOD-323 (mechanical compatibility)
• Mounting Type: Surface Mount (assembly process compatibility)
• Operating Temperature Range: -65°C to 150°C (thermal envelope compatibility)
• RoHS3 Compliance: Required for regulatory alignment

Secondary Compatibility Parameters:

• Power - Max: 300 mW (primary specification) or lower ratings with design verification
• Impedance (Max): 130 Ohms (reference specification)
• Current - Reverse Leakage: 50 nA (reference specification)
• Voltage - Forward (Vf): 900 mV @ 10 mA (reference specification)

Substitute parts meeting all primary criteria are classified as direct equivalents. Parts with reduced power ratings or modified impedance characteristics remain functionally compatible within the specified electrical envelope but require application-level validation.

Parameter Comparison

Engineering Selection Recommendations

MM3Z39VT1G (onsemi)

This substitute is the primary equivalent for the MM3Z39VST1G. Both components share identical electrical specifications including 39 V Zener voltage, 300 mW power rating, 130 Ohms maximum impedance, and matching forward voltage characteristics. The MM3Z39VT1G maintains active product status with ROHS3 compliance and unlimited moisture sensitivity rating. The ±5% tolerance specification provides acceptable voltage regulation performance. This part is available in high inventory quantities (44,400 pcs) and is suitable for direct replacement in all applications where the MM3Z39VST1G was originally specified.

DDZ39FS-7 (Diodes Incorporated)

This substitute provides functional equivalence with the following considerations: The Zener voltage (39 V) and operating temperature range (-65°C to 150°C) match the original specification. The DDZ39FS-7 features a reduced power rating of 200 mW compared to the 300 mW specification of the MM3Z39VST1G. The impedance is reduced to 85 Ohms, and the tolerance is tighter at ±3%. This component is suitable for applications where the 200 mW power dissipation envelope is sufficient. The DDZ39FS-7 maintains active product status, ROHS3 compliance, and unlimited moisture sensitivity rating. Component selection between the 300 mW and 200 mW options depends on circuit power dissipation requirements.

Frequently Asked Questions (FAQ)

Q: Can MM3Z39VT1G be used as a direct replacement for MM3Z39VST1G?

A: Yes. Both components are manufactured by onsemi with identical Zener voltage (39 V), power rating (300 mW), impedance (130 Ohms), forward voltage characteristics (900 mV @ 10 mA), and operating temperature range (-65°C to 150°C). The primary difference is product status: MM3Z39VST1G is obsolete while MM3Z39VT1G is active. Both are packaged in SOD-323 and comply with ROHS3 standards.

Q: What is the key difference between MM3Z39VT1G and DDZ39FS-7?

A: The primary difference is power rating. MM3Z39VT1G is rated at 300 mW while DDZ39FS-7 is rated at 200 mW. Additionally, DDZ39FS-7 has lower impedance (85 Ohms vs. 130 Ohms) and tighter tolerance (±3% vs. ±5%). Both maintain the 39 V Zener voltage and SOD-323 package. Selection depends on circuit power dissipation requirements.

Q: Are all substitute parts in the same package?

A: Yes. All listed parts (MM3Z39VST1G, MM3Z39VT1G, and DDZ39FS-7) use the SOD-323 package (SC-76 case). This ensures mechanical and assembly compatibility across all substitutes.

Q: What compliance certifications apply to these parts?

A: All parts are ROHS3 compliant and have moisture sensitivity level 1 (unlimited). All are REACH unaffected and classified under ECCN EAR99 with HTSUS code 8541.10.0050.

Q: Can DDZ39FS-7 be used in high-power dissipation applications?

A: DDZ39FS-7 is rated at 200 mW maximum power dissipation. Applications requiring sustained power dissipation above 200 mW should use MM3Z39VT1G (300 mW rating) to ensure reliable operation within thermal limits.

Q: What is the tolerance difference between substitutes?

A: MM3Z39VST1G has no specified tolerance. MM3Z39VT1G specifies ±5% tolerance. DDZ39FS-7 specifies ±3% tolerance. Tighter tolerance (±3%) provides more precise voltage regulation but does not affect functional compatibility in standard applications.

Q: Are there inventory considerations for part selection?

A: MM3Z39VT1G has significantly higher inventory availability (44,400 pcs) compared to DDZ39FS-7 (765 pcs). For applications with extended production timelines, MM3Z39VT1G offers superior supply chain continuity.