SMBJ5942B-TP Equivalent & Substitute Parts

Part Overview

The SMBJ5942B-TP is a Zener diode manufactured by Micro Commercial Co, rated at 51 V nominal voltage with 1.5 W maximum power dissipation. This component operates in the surface mount DO-214AA (SMB) package and is designed for interface applications requiring voltage regulation and transient protection. The part maintains Active product status with full inventory availability.

Substitute parts are identified when electrical parameters—including Zener voltage, tolerance, impedance, and reverse leakage characteristics—remain within acceptable ranges, while packaging and thermal specifications remain compatible with the original design requirements.

Substiute Parts

SMBJ5942B-TP

Micro Commercial CoIn Stock: 830SMBJ5942B-TP Datasheet

Current PartRFQ

SZ1SMB5942BT3G

onsemiIn Stock: 3085SZ1SMB5942BT3G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMBJ5942B-TP is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Zener voltage (Vz) must equal 51 V nominal
• Tolerance must be ±5% or tighter
• Impedance (Zzt) maximum must not exceed 70 Ohms
• Reverse leakage current must not exceed 1 µA @ 38.8 V
• Forward voltage characteristics must remain within specified limits

Mechanical & Thermal Compatibility Criteria:

• Package must be DO-214AA (SMB) surface mount
• Operating temperature range must encompass or exceed -55°C to 150°C
• Mounting type must be surface mount

Functional Substitution Logic: The SZ1SMB5942BT3G qualifies as a direct substitute because it maintains identical Zener voltage (51 V), tolerance (±5%), impedance (70 Ohms maximum), and reverse leakage specifications (1 µA @ 38.8 V). Although the maximum power rating is higher (3 W versus 1.5 W), this represents an enhancement in thermal capability and does not compromise circuit compatibility. The part operates within the required temperature range and uses the same SMB package configuration.

Parameter Comparison

Engineering Selection Recommendations

SMBJ5942B-TP (Original Part):

• Active product status with established supply chain
• Bulk packaging suitable for high-volume manufacturing environments
• REACH Unaffected classification
• Recommended for applications where 1.5 W power dissipation is sufficient and bulk packaging is preferred

SZ1SMB5942BT3G (Substitute Part):

• Active product status with higher inventory availability (2988 Pcs in stock)
• Tape & Reel packaging optimized for automated assembly processes
• AEC-Q101 automotive qualification and ROHS3 compliance
• Extended operating temperature range (-65°C to 150°C) provides additional thermal margin
• Higher power rating (3 W) accommodates transient energy absorption without thermal stress
• Moisture Sensitivity Level 1 (Unlimited) indicates superior moisture resistance
• Recommended for applications requiring automotive-grade reliability, automated assembly, or enhanced thermal performance

Both parts maintain identical electrical specifications for Zener voltage, tolerance, impedance, and reverse leakage characteristics, ensuring functional equivalence in circuit operation.

Frequently Asked Questions (FAQ)

Q: Can SZ1SMB5942BT3G replace SMBJ5942B-TP in existing designs?

A: Yes. Both parts maintain identical Zener voltage (51 V), tolerance (±5%), impedance (70 Ohms), and reverse leakage specifications (1 µA @ 38.8 V). The SMB package footprint is identical, enabling direct PCB substitution without layout modification.

Q: What is the significance of the higher power rating in SZ1SMB5942BT3G?

A: The 3 W rating in SZ1SMB5942BT3G versus 1.5 W in SMBJ5942B-TP represents increased thermal dissipation capability. This allows the substitute part to handle transient energy pulses without exceeding junction temperature limits, providing additional design margin in protection circuits.

Q: How do packaging differences affect substitution?

A: SMBJ5942B-TP is supplied in Bulk packaging, while SZ1SMB5942BT3G uses Tape & Reel (TR) format. Both are surface mount DO-214AA (SMB) packages with identical PCB footprints. Packaging selection depends on manufacturing process: Bulk suits manual or semi-automated assembly, while Tape & Reel optimizes high-speed automated pick-and-place operations.

Q: Does the extended temperature range of SZ1SMB5942BT3G affect compatibility?

A: No. The substitute part's operating range (-65°C to 150°C) encompasses the original part's range (-55°C to 150°C). Extended temperature capability provides additional design margin without introducing incompatibility.

Q: What compliance certifications differ between the parts?

A: SZ1SMB5942BT3G includes AEC-Q101 automotive qualification and ROHS3 compliance, making it suitable for automotive and regulated applications. SMBJ5942B-TP carries REACH Unaffected status. Both parts are REACH Unaffected and classified as EAR99 for export purposes.

Q: Are there electrical performance differences in forward voltage characteristics?

A: Forward voltage specifications differ: SMBJ5942B-TP specifies 1.5 V @ 200 mA, while SZ1SMB5942BT3G specifies 900 mV @ 10 mA. These measurements occur at different test currents and do not indicate incompatibility. Both values fall within acceptable ranges for Zener diode forward conduction characteristics.