MMBZ5242B-TP Equivalent & Substitute Parts

Part Overview

The MMBZ5242B-TP is a Zener diode manufactured by Micro Commercial Co, rated at 12 V nominal with 350 mW maximum power dissipation in a surface mount SOT-23 package. This component is classified as Active and maintains full RoHS3 compliance. Zener diodes of this specification are used in voltage regulation, overvoltage protection, and reference voltage circuits. Substitute parts are identified to provide design flexibility when the primary part is unavailable or when alternative sourcing is required while maintaining electrical and mechanical compatibility.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	12	V
Tolerance	±5%	%
Power - Max	350	mW
Impedance (Max)	30	Ohms
Current - Reverse Leakage @ Vr	1	µA @ 9.1 V
Voltage - Forward (Vf) (Max) @ If	900	mV @ 10 mA
Operating Temperature Range	-55 to 150	°C (TJ)
Package / Case	SOT-23-3 (TO-236)	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the MMBZ5242B-TP is determined by strict equivalence in the following critical parameters:

Zener Voltage (Vz): Must be 12 V nominal with ±5% tolerance
Package Type: Must be SOT-23-3 (TO-236, SC-59) for mechanical and thermal compatibility
Mounting Configuration: Must be Surface Mount
Impedance (Zzt): Maximum 30 Ohms
Reverse Leakage Current: 1 µA @ 9.1 V
Forward Voltage: 900 mV maximum @ 10 mA
Compliance: RoHS3 and REACH Unaffected status required

The substitute part MMBZ5242BLT1G from onsemi meets all electrical parameter requirements. The primary difference is maximum power dissipation (225 mW versus 350 mW), which represents a derating condition. This substitute is suitable for applications where the thermal load does not exceed 225 mW continuous operation.

Parameter Comparison

Parameter	MMBZ5242B-TP (Micro Commercial Co)	MMBZ5242BLT1G (onsemi)	Compatibility
Voltage - Zener (Nom)	12 V	12 V	Equivalent
Tolerance	±5%	±5%	Equivalent
Power - Max	350 mW	225 mW	Substitute Derated
Impedance (Max)	30 Ohms	30 Ohms	Equivalent
Current - Reverse Leakage @ Vr	1 µA @ 9.1 V	1 µA @ 9.1 V	Equivalent
Voltage - Forward (Vf) (Max) @ If	900 mV @ 10 mA	900 mV @ 10 mA	Equivalent
Operating Temperature Range	-55°C to 150°C	-65°C to 150°C	Substitute Extended
Package / Case	SOT-23-3 (TO-236)	SOT-23-3 (TO-236)	Equivalent
Mounting Type	Surface Mount	Surface Mount	Equivalent
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	Equivalent
REACH Status	REACH Unaffected	REACH Unaffected	Equivalent

Engineering Selection Recommendations

MMBZ5242B-TP (Primary Part) is the specified component with 350 mW power rating and operating temperature range of -55°C to 150°C. This part maintains Active product status with full RoHS3 and REACH compliance. Selection is appropriate for applications requiring maximum power dissipation within the specified thermal envelope.

MMBZ5242BLT1G (Substitute Part) from onsemi is suitable as an alternative when the primary part is unavailable. This substitute maintains electrical equivalence across all critical parameters: zener voltage, tolerance, impedance, leakage current, and forward voltage. The substitute provides an extended lower operating temperature limit (-65°C versus -55°C), which is advantageous for cold environment applications. However, the maximum power dissipation is derated to 225 mW. Selection of this substitute requires verification that circuit thermal load does not exceed 225 mW continuous operation. Both parts are RoHS3 compliant and REACH unaffected, meeting regulatory requirements for equivalent applications.

Frequently Asked Questions (FAQ)

Q: Can MMBZ5242BLT1G be used as a direct replacement for MMBZ5242B-TP?

A: MMBZ5242BLT1G is electrically compatible for zener voltage regulation and reference applications. The primary consideration is power dissipation: the substitute is rated at 225 mW maximum versus 350 mW for the original part. Direct substitution is valid only when circuit thermal load remains below 225 mW continuous operation.

Q: Are the package dimensions identical between these parts?

A: Both parts use the SOT-23-3 package (also designated TO-236 or SC-59). Package footprint, lead spacing, and mounting requirements are identical, enabling direct PCB layout compatibility without modification.

Q: What is the difference in operating temperature range?

A: MMBZ5242B-TP operates from -55°C to 150°C junction temperature. MMBZ5242BLT1G extends the lower limit to -65°C. Both maintain the same upper temperature limit of 150°C. The substitute provides broader low-temperature capability.

Q: Do both parts meet the same compliance standards?

A: Yes. Both MMBZ5242B-TP and MMBZ5242BLT1G are RoHS3 compliant and REACH unaffected. They are equivalent for regulatory and environmental compliance purposes.

Q: What parameters must remain constant for substitution?

A: Zener voltage (12 V ±5%), impedance (30 Ohms maximum), reverse leakage current (1 µA @ 9.1 V), forward voltage (900 mV @ 10 mA), and package type (SOT-23-3) must remain constant. These parameters define functional equivalence in voltage regulation and protection circuits.

Q: Is the 225 mW power rating of the substitute sufficient for typical applications?

A: Sufficiency depends on circuit design. Applications with continuous power dissipation below 225 mW operate within the substitute's thermal rating. Applications requiring sustained dissipation above 225 mW require the original 350 mW part or thermal management modifications.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message