MMSZ24T1 Equivalent & Substitute Parts

Part Overview

The MMSZ24T1 is a 24 V Zener diode rated at 500 mW in SOD-123 surface mount packaging, manufactured by onsemi. This component is classified as obsolete, indicating discontinuation from the manufacturer. The identification of equivalent and substitute parts is necessary to maintain design continuity and ensure component availability for new production runs, repairs, and ongoing system support.

Key Parameters

Parameter	Value
Voltage - Zener (Nom)	24 V
Tolerance	±5%
Power - Max	500 mW
Impedance (Max)	70 Ohms
Current - Reverse Leakage @ Vr	50 nA @ 16.8 V
Voltage - Forward (Vf) (Max) @ If	900 mV @ 10 mA
Operating Temperature Range	-55°C to 150°C
Mounting Type	Surface Mount
Package / Case	SOD-123
RoHS Status	RoHS non-compliant
Moisture Sensitivity Level	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the MMSZ24T1 is determined by strict adherence to the following electrical and mechanical parameters:

Critical Parameters for Substitution:

Zener voltage: 24 V nominal
Package type: SOD-123 surface mount
Operating temperature range: -55°C to 150°C
Mounting type: Surface mount

Allowable Parameter Variations:

Power rating: The MMSZ24T1 is rated at 500 mW. Substitute parts with lower power ratings (410 mW) are acceptable for applications where the full 500 mW capability is not required.
Tolerance: The MMSZ24T1 specifies ±5% tolerance. Substitute parts with tighter tolerance (±2%) are acceptable as they meet or exceed the original specification.
Reverse leakage current: Variations in reverse leakage specifications are acceptable provided the parts maintain the same zener voltage and temperature range.

Substitute Categories:

Direct Equivalent: MMSZ24T1G maintains identical electrical specifications and differs only in packaging format (Tape & Reel) and product status (Active vs. Obsolete).

Parametric Equivalent: SZMMSZ24T1G provides identical electrical specifications with automotive-grade qualification (AEC-Q101) and RoHS3 compliance.

Similar Alternatives: BZT52 series parts (Vishay) maintain the 24 V zener voltage, SOD-123 package, and operating temperature range. These parts feature 410 mW power rating and ±2% tolerance, representing a reduction in power dissipation capability but improved voltage tolerance.

Parameter Comparison

Part Number	Manufacturer	Vz (Nom)	Tolerance	Power (Max)	Zzt (Max)	Vf (Max) @ If	Temp Range	Package	Product Status	RoHS Status
MMSZ24T1	onsemi	24 V	±5%	500 mW	70 Ω	900 mV @ 10 mA	-55°C to 150°C	SOD-123	Obsolete	Non-compliant
MMSZ24T1G	onsemi	24 V	±5%	500 mW	70 Ω	900 mV @ 10 mA	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
SZMMSZ24T1G	onsemi	24 V	±5%	500 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52B24-E3-08	Vishay	24 V	±2%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52B24-E3-18	Vishay	24 V	±2%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52B24-G3-08	Vishay	24 V	±2%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52B24-G3-18	Vishay	24 V	±2%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52C24-E3-08	Vishay	24 V	±5%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52C24-E3-18	Vishay	24 V	±5%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52C24-G3-08	Vishay	24 V	±5%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant
BZT52C24-G3-18	Vishay	24 V	±5%	410 mW	70 Ω	—	-55°C to 150°C	SOD-123	Active	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications):

MMSZ24T1G is the primary direct equivalent. This part maintains all electrical specifications of the original MMSZ24T1 while offering active product status and RoHS3 compliance. The difference in packaging format (Tape & Reel vs. bulk) does not affect electrical performance and accommodates modern manufacturing processes.

For Automotive and Regulated Applications:

SZMMSZ24T1G is specified for applications requiring automotive-grade components with AEC-Q101 qualification. This part maintains identical electrical specifications while providing enhanced reliability documentation and RoHS3 compliance.

For Applications with Reduced Power Dissipation Requirements:

The BZT52 series (both B and C variants) from Vishay provides active alternatives with 410 mW power rating. These parts are suitable for applications where the full 500 mW capability of the original part is not required. The BZT52C24 variants match the ±5% tolerance of the MMSZ24T1, while BZT52B24 variants offer improved ±2% tolerance.

Compliance Considerations:

All recommended substitute parts carry RoHS3 compliance, addressing regulatory requirements that the original MMSZ24T1 does not meet. For applications subject to RoHS directives, MMSZ24T1G or SZMMSZ24T1G are mandatory selections.

Packaging Format Selection:

The suffix designations (-E3-08, -E3-18, -G3-08, -G3-18) indicate packaging format variations. The -E3 suffix denotes Cut Tape & Digi-Reel packaging, while -G3 denotes Tape & Reel packaging. Selection between these formats depends on assembly equipment compatibility and procurement volume requirements.

Frequently Asked Questions (FAQ)

Q: Can BZT52 series parts with 410 mW rating replace the 500 mW MMSZ24T1 in all applications?

A: BZT52 series substitution is valid only for applications where power dissipation does not exceed 410 mW. Circuit designs that depend on the full 500 mW capability require MMSZ24T1G or SZMMSZ24T1G. Power dissipation is determined by the application's forward current and reverse voltage conditions.

Q: What is the difference between BZT52B24 and BZT52C24 variants?

A: The primary difference is voltage tolerance. BZT52B24 variants specify ±2% tolerance, while BZT52C24 variants specify ±5% tolerance. Both maintain identical 24 V nominal zener voltage, 410 mW power rating, and SOD-123 packaging. Selection depends on circuit tolerance requirements.

Q: Are the packaging format suffixes (-E3-08, -E3-18, -G3-08, -G3-18) electrically significant?

A: No. These suffixes indicate packaging and tape configuration only. -E3 denotes Cut Tape & Digi-Reel format, while -G3 denotes standard Tape & Reel format. Electrical specifications remain identical across these variants. Selection is based on assembly equipment compatibility and procurement logistics.

Q: Is MMSZ24T1G a direct drop-in replacement for MMSZ24T1?

A: Yes. MMSZ24T1G maintains identical electrical specifications, operating temperature range, and SOD-123 package. The only differences are product status (Active vs. Obsolete) and RoHS compliance. No circuit modifications are required.

Q: What is the significance of the SZMMSZ24T1G automotive qualification?

A: SZMMSZ24T1G carries AEC-Q101 automotive qualification, indicating compliance with automotive industry reliability and testing standards. This part is required for automotive applications or systems subject to automotive-grade component specifications. Non-automotive applications may use MMSZ24T1G.

Q: Can I use BZT52 parts in place of onsemi MMSZ24 parts in existing designs?

A: BZT52 substitution is valid provided the application power dissipation does not exceed 410 mW and the circuit tolerates the ±2% or ±5% voltage specification. Cross-manufacturer substitution requires verification that reverse leakage current specifications meet circuit requirements. The impedance specification (70 Ohms maximum) is identical across all parts listed.

Q: Why is the original MMSZ24T1 marked as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. MMSZ24T1G provides continuity by offering identical specifications in an active product line. Existing inventory of MMSZ24T1 may be available through component distributors, but MMSZ24T1G is the recommended long-term solution.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All recommended substitute parts carry RoHS3 compliance. The original MMSZ24T1 is RoHS non-compliant. For applications subject to RoHS directives or customer requirements, substitute parts must be selected from the compliant alternatives listed.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message