MMSZ28VCF Zener Diode 28V 1W Equivalent & Substitute Parts

Part Overview

The MMSZ28VCF is a surface mount Zener diode manufactured by onsemi, rated for 28 V nominal Zener voltage with 1 W maximum power dissipation in SOD-123F packaging. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The part operates at a maximum junction temperature of 150°C and maintains ±5% voltage tolerance across its operating range.

Substiute Parts

MMSZ28VCF

onsemiIn Stock: 915MMSZ28VCF Datasheet

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MMSZ27T1G

onsemiIn Stock: 50284MMSZ27T1G Datasheet

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ACZRM5255B-HF

Comchip TechnologyIn Stock: 1101ACZRM5255B-HF Datasheet

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ACZRW5255B-G

Comchip TechnologyIn Stock: 1142ACZRW5255B-G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMSZ28VCF is determined by the following critical parameters:

Primary Substitution Criteria:

• Zener voltage (Vz): 28 V nominal with ±5% tolerance
• Package type: SOD-123F surface mount
• Mounting type: Surface mount
• RoHS3 compliance
• Moisture sensitivity level: 1 (Unlimited)

Secondary Compatibility Factors:

• Power dissipation capability (minimum 1 W for direct replacement; lower ratings acceptable for reduced power applications)
• Impedance characteristics (Zzt)
• Reverse leakage current specifications
• Operating temperature range

The substitute parts listed below meet the primary criteria for direct substitution in applications requiring 28 V Zener regulation in SOD-123F packaging. Power rating variations indicate suitability for different thermal environments and load conditions.

Parameter Comparison

Engineering Selection Recommendations

ACZRM5255B-HF and ACZRW5255B-G (Comchip Technology): These parts provide direct substitution for the MMSZ28VCF with identical 28 V Zener voltage and SOD-123F packaging. Both are active products with ROHS3 compliance and AEC-Q101 automotive qualification. The ACZRM5255B-HF offers 500 mW power rating, while the ACZRW5255B-G provides 350 mW. Selection between these depends on thermal dissipation requirements in the application. Both feature lower impedance (44 Ohms) compared to the main part (15 Ohms) and reduced reverse leakage current (100 nA vs. 1 µA), resulting in improved regulation characteristics. Extended operating temperature range (-65°C to 150°C for ACZRW5255B-G; -55°C to 150°C for ACZRM5255B-HF) supports broader environmental applications.

MMSZ27T1G (onsemi): This part represents a voltage-variant substitute with 27 V nominal Zener voltage instead of 28 V. It is an active product with ROHS3 compliance and maintains the same ±5% tolerance. The SOD-123 package differs from the SOD-123F of the main part, requiring PCB layout verification. The 500 mW power rating is lower than the main part's 1 W specification. This substitute is suitable only for applications where 27 V regulation is acceptable within system design tolerances.

Compliance and Availability: All substitute parts maintain ROHS3 compliance and unlimited moisture sensitivity level (MSL 1), ensuring compatibility with standard manufacturing and storage practices. The Comchip Technology parts carry AEC-Q101 automotive qualification, providing additional assurance for automotive and high-reliability applications.

Frequently Asked Questions (FAQ)

Q: Can ACZRM5255B-HF or ACZRW5255B-G be used as direct replacements for MMSZ28VCF?

A: Yes. Both Comchip Technology parts maintain the same 28 V Zener voltage, ±5% tolerance, and SOD-123F packaging as the MMSZ28VCF. They are active products with ROHS3 compliance. Power rating differences (500 mW and 350 mW respectively, versus 1 W for the main part) require thermal analysis to confirm suitability for your specific application's power dissipation profile.

Q: What is the difference between SOD-123 and SOD-123F packaging?

A: SOD-123F is a variant of SOD-123 with different lead geometry and footprint dimensions. The MMSZ27T1G uses SOD-123 packaging, while the main part and the Comchip substitutes use SOD-123F. PCB layout and footprint compatibility must be verified before substitution.

Q: Why does MMSZ27T1G have a different Zener voltage (27 V vs. 28 V)?

A: MMSZ27T1G is a voltage-variant substitute within the onsemi MMSZ series. It is listed as an available substitute but introduces a 1 V difference in regulation voltage. This part is suitable only for applications where 27 V operation falls within acceptable system design parameters.

Q: What are the advantages of the Comchip Technology substitutes over the main part?

A: The ACZRM5255B-HF and ACZRW5255B-G offer lower impedance (44 Ohms vs. 15 Ohms), reduced reverse leakage current (100 nA vs. 1 µA), extended operating temperature ranges, and AEC-Q101 automotive qualification. These characteristics provide improved voltage regulation stability and reliability. Both are active products with established supply availability.

Q: Is the MMSZ28VCF still available for procurement?

A: The MMSZ28VCF is classified as obsolete. Active substitute parts (ACZRM5255B-HF, ACZRW5255B-G, and MMSZ27T1G) are recommended for new designs and ongoing procurement to ensure supply continuity.

Q: Do all substitute parts meet RoHS3 compliance?

A: Yes. All listed substitute parts are ROHS3 compliant with unlimited moisture sensitivity level (MSL 1), matching the compliance profile of the main part.