MMBZ5234B Equivalent & Substitute Parts

Part Overview

The MMBZ5234B is a 6.2 V Zener diode rated at 350 mW in a surface mount SOT-23-3 package, manufactured by onsemi. This component is classified as obsolete, though 5682 units remain in stock. The part operates across a temperature range of -55°C to 150°C with ±5% voltage tolerance and is suitable for voltage regulation and protection applications in electronic circuits.

Due to the obsolete status of the MMBZ5234B, identifying equivalent and substitute parts is necessary for design continuity, long-term supply chain reliability, and access to active product lines with extended availability and compliance certifications.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nominal)	6.2	V
Tolerance	±5%	—
Power - Maximum	350	mW
Impedance (Maximum)	7	Ohms
Current - Reverse Leakage @ Vr	5	µA @ 4 V
Voltage - Forward (Maximum) @ If	900	mV @ 10 mA
Operating Temperature Range	-55 to 150	°C
Mounting Type	Surface Mount	—
Package / Case	TO-236-3, SC-59, SOT-23-3	—

Substitute Part Grouping Explanation

Substitution of the MMBZ5234B is determined by the following critical parameters:

Primary Matching Criteria:

Zener voltage: 6.2 V nominal
Package type: SOT-23-3 (TO-236-3, SC-59)
Mounting: Surface mount
Tolerance: ±5% or tighter

Secondary Compatibility Factors:

Maximum power rating: 350 mW or higher
Impedance: 7 Ohms or lower
Reverse leakage current: 5 µA @ 4 V or lower
Forward voltage: 900 mV @ 10 mA or lower
Operating temperature range: Must encompass -55°C to 150°C or be compatible with application requirements

Substitute parts are grouped into three categories:

Direct Equivalents – Identical electrical specifications and package; different manufacturers or packaging formats
Functional Equivalents – Same zener voltage and package; minor variations in power rating, impedance, or leakage current within acceptable operating margins
Upgraded Alternatives – Enhanced specifications (tighter tolerance, lower impedance, improved temperature range) suitable for higher-reliability applications

Parameter Comparison

Part Number	Manufacturer	Vz (V)	Tolerance	Power (mW)	Zzt (Ohms)	Ir @ 4V (µA)	Vf @ 10mA (mV)	Temp Range (°C)	Package	Status
MMBZ5234B	onsemi	6.2	±5%	350	7	5	900	-55 to 150	SOT-23-3	Obsolete
MMBZ5234BLT1G	onsemi	6.2	±5%	225	7	5	900	-65 to 150	SOT-23-3	Active
SZMMBZ5234BLT1G	onsemi	6.2	±5%	225	7	5	900	-65 to 150	SOT-23-3	Active
CMPZ5234B BK PBFREE	Central Semiconductor Corp	6.2	±5%	350	7	5	900	-65 to 150	SOT-23-3	Active
CMPZ5234B TR PBFREE	Central Semiconductor Corp	6.2	±5%	350	7	5	900	-65 to 150	SOT-23-3	Active
MMBZ5234B-7-F	Diodes Incorporated	6.2	±5%	350	7	5	900	-65 to 150	SOT-23-3	Active
BZX84-A6V2,215	Nexperia USA Inc.	6.2	±1%	250	10	3	900	-65 to 150	SOT-23-3	Active
BZX84B6V2-7-F	Diodes Incorporated	6.2	±2%	300	10	3	900	-65 to 150	SOT-23-3	Active
BZX84B6V2Q-7-F	Diodes Incorporated	6.2	±2%	300	10	3	900	-65 to 150	SOT-23-3	Active
BZX84C6V2 TR	Central Semiconductor Corp	6.2	±5%	350	10	3	900	-65 to 150	SOT-23-3	Active
BZX84C6V2-TP	Micro Commercial Co	6.2	±5%	350	10	3	900	-55 to 150	SOT-23-3	Active

Engineering Selection Recommendations

Direct Equivalents (Recommended for Drop-In Replacement):

The MMBZ5234B-7-F (Diodes Incorporated) and CMPZ5234B TR PBFREE (Central Semiconductor Corp) are direct functional equivalents with identical electrical specifications (6.2 V, ±5%, 350 mW, 7 Ohms impedance). Both are active products with RoHS3 compliance and extended operating temperature ranges (-65°C to 150°C), providing superior supply chain continuity compared to the obsolete MMBZ5234B. The MMBZ5234B-7-F offers the highest inventory availability (137,200 units) and is suitable for immediate design transitions.

Active onsemi Alternatives:

The MMBZ5234BLT1G and SZMMBZ5234BLT1G are active onsemi products with identical zener voltage and impedance specifications. These parts operate at reduced power ratings (225 mW versus 350 mW) and are suitable for applications where the lower power dissipation is acceptable. The SZMMBZ5234BLT1G includes AEC-Q101 automotive qualification, making it appropriate for automotive-grade designs.

Enhanced Specification Options:

The BZX84-A6V2,215 (Nexperia) and BZX84B6V2-7-F (Diodes Incorporated) offer tighter voltage tolerance (±1% and ±2% respectively) and lower reverse leakage current (3 µA versus 5 µA), suitable for precision voltage regulation applications. The BZX84B6V2Q-7-F includes AEC-Q101 automotive qualification for regulated automotive environments.

Compliance and Certification:

All recommended substitute parts carry RoHS3 compliance and REACH Unaffected status, matching the environmental and regulatory requirements of the original MMBZ5234B. Parts designated with AEC-Q101 qualification (SZMMBZ5234BLT1G, BZX84-A6V2,215, BZX84B6V2Q-7-F) are suitable for automotive applications requiring formal qualification.

Frequently Asked Questions (FAQ)

Q: Can the MMBZ5234BLT1G replace the MMBZ5234B in all applications?

A: The MMBZ5234BLT1G is electrically compatible for applications where the 225 mW power rating is sufficient. If the circuit requires the full 350 mW dissipation capability of the original part, the MMBZ5234B-7-F or CMPZ5234B TR PBFREE are required. Both maintain identical impedance (7 Ohms) and voltage specifications.

Q: What is the difference between CMPZ5234B BK PBFREE and CMPZ5234B TR PBFREE?

A: Both parts are electrically identical 6.2 V, 350 mW zener diodes from Central Semiconductor Corp. The difference is packaging format: BK PBFREE is supplied in bulk, while TR PBFREE is supplied in tape and reel format. Selection depends on assembly process requirements and inventory management practices.

Q: Are the BZX84 series parts compatible with the MMBZ5234B?

A: BZX84 series parts (BZX84C6V2 TR, BZX84C6V2-TP, BZX84B6V2-7-F) are functionally compatible with identical 6.2 V zener voltage and SOT-23-3 packaging. However, they feature higher impedance (10 Ohms versus 7 Ohms) and lower reverse leakage current (3 µA versus 5 µA). These differences are acceptable in most voltage regulation and protection circuits but should be verified in precision applications.

Q: Why does the MMBZ5234B-7-F have a wider operating temperature range than the original MMBZ5234B?

A: The MMBZ5234B-7-F extends the lower operating temperature limit from -55°C to -65°C, providing enhanced performance in cold environments. This is a specification improvement with no negative impact on existing designs. The upper temperature limit remains 150°C.

Q: Is the BZX84-A6V2,215 suitable for high-precision voltage reference applications?

A: The BZX84-A6V2,215 offers ±1% voltage tolerance and lower reverse leakage current (3 µA), making it suitable for precision voltage regulation. However, the 250 mW power rating is lower than the original 350 mW specification. Verify that the application power dissipation requirements do not exceed 250 mW before selection.

Q: What is the significance of AEC-Q101 qualification on certain substitute parts?

A: AEC-Q101 qualification indicates that the part meets automotive industry reliability and quality standards. Parts bearing this qualification (SZMMBZ5234BLT1G, BZX84-A6V2,215, BZX84B6V2Q-7-F) are suitable for automotive applications requiring formal supplier qualification. Non-automotive applications do not require this certification.

Q: Can I use the MMBZ5234B-7-F in place of the MMBZ5234B without circuit modifications?

A: Yes. The MMBZ5234B-7-F is a direct electrical equivalent with identical zener voltage (6.2 V), tolerance (±5%), power rating (350 mW), and impedance (7 Ohms). The SOT-23-3 package is identical. No circuit modifications are required for drop-in replacement.

Q: What packaging options are available for the MMBZ5234B substitute parts?

A: Substitute parts are available in multiple packaging formats: Cut Tape (CT) & Digi-Reel (MMBZ5234BLT1G), Tape & Reel (TR) (SZMMBZ5234BLT1G, MMBZ5234B-7-F, BZX84 series), and Bulk (CMPZ5234B BK PBFREE). Selection depends on assembly equipment compatibility and production volume requirements.

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