1SMB5940H Zener Diode Equivalent & Substitute Parts

Part Overview

The 1SMB5940H is an active-status Zener diode manufactured by Taiwan Semiconductor Corporation, rated for 43 V nominal Zener voltage with 3 W maximum power dissipation in a surface mount DO-214AA (SMB) package. This component is designed for voltage regulation and protection applications in automotive-grade circuits. Substitute parts are identified to provide alternative sourcing options while maintaining electrical and mechanical compatibility within specified parameter tolerances.

Substiute Parts

1SMB5940H

Taiwan Semiconductor CorporationIn Stock: 6571SMB5940H Datasheet

Current PartRFQ

SZ1SMB5940BT3G

onsemiIn Stock: 3634SZ1SMB5940BT3G Datasheet

UpgradeRFQ

1SMB5940BT3G

onsemiIn Stock: 117561SMB5940BT3G Datasheet

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SMBJ5367B-TP

Micro Commercial CoIn Stock: 8362SMBJ5367B-TP Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 1SMB5940H are qualified based on the following critical parameters that determine functional equivalence:

Primary Equivalence Criteria:

• Voltage - Zener (Nom): 43 V
• Tolerance: ±5%
• Package / Case: DO-214AA, SMB
• Mounting Type: Surface Mount
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)

Secondary Compatibility Parameters:

• Power - Max: 3 W or greater
• Impedance (Max): 53 Ohms or lower
• Current - Reverse Leakage @ Vr: 1 µA @ 32.7 V or lower
• Operating Temperature Range: Must encompass -55°C to 150°C or provide equivalent coverage
• Grade: Automotive
• Qualification: AEC-Q101

Parts meeting all primary criteria and maintaining or exceeding secondary parameter specifications are classified as direct substitutes. Parts with enhanced power ratings (5 W) or improved impedance characteristics are classified as upgrades suitable for applications requiring higher thermal margin or lower dynamic impedance.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Electrical and Mechanical Equivalence):

SZ1SMB5940BT3G and 1SMB5940BT3G (both onsemi) are direct substitutes for the 1SMB5940H. Both parts maintain identical Zener voltage (43 V), tolerance (±5%), power rating (3 W), impedance (53 Ohms), and reverse leakage specifications. Both are AEC-Q101 qualified automotive-grade components with ROHS3 compliance and MSL 1 rating. The SZ1SMB5940BT3G provides extended lower operating temperature range (-65°C vs. -55°C), offering enhanced cold-temperature performance. The 1SMB5940BT3G maintains the same temperature range as the main part. Both are suitable for direct pin-and-function replacement.

Upgrade Substitute (Enhanced Performance):

SMBJ5367B-TP (Micro Commercial Co) is classified as an upgrade substitute. While maintaining the 43 V Zener voltage and ±5% tolerance, this part provides superior performance characteristics: 5 W maximum power (67% higher than the main part), 20 Ohms maximum impedance (62% lower than the main part), and 500 nA reverse leakage (50% lower than the main part). The SMBJ5367B-TP is suitable for applications requiring higher thermal dissipation capability or lower dynamic impedance. All parts maintain automotive-grade qualification, ROHS3 compliance, and MSL 1 rating.

Frequently Asked Questions (FAQ)

Q: Can SZ1SMB5940BT3G replace 1SMB5940H in all applications?

A: Yes. SZ1SMB5940BT3G is a direct electrical and mechanical equivalent with identical Zener voltage (43 V), tolerance (±5%), power rating (3 W), and impedance (53 Ohms). Both are AEC-Q101 qualified, ROHS3 compliant, and packaged in DO-214AA (SMB). The extended temperature range of SZ1SMB5940BT3G (-65°C to 150°C vs. -55°C to 150°C) provides additional cold-temperature margin without affecting circuit operation.

Q: What is the difference between 1SMB5940BT3G and SZ1SMB5940BT3G?

A: Both are onsemi products with identical electrical specifications (43 V, ±5%, 3 W, 53 Ohms impedance, 1 µA reverse leakage). The primary difference is the operating temperature range: SZ1SMB5940BT3G operates from -65°C to 150°C, while 1SMB5940BT3G operates from -65°C to 150°C. Both are suitable direct substitutes for the 1SMB5940H.

Q: When should SMBJ5367B-TP be selected instead of the main part?

A: SMBJ5367B-TP is selected when applications require higher power dissipation capability (5 W vs. 3 W) or lower dynamic impedance (20 Ohms vs. 53 Ohms). The lower impedance provides improved voltage regulation performance under transient conditions. The higher power rating accommodates designs with greater thermal stress. Zener voltage (43 V) and tolerance (±5%) remain identical, ensuring voltage regulation specifications are maintained.

Q: Are all substitute parts automotive-grade qualified?

A: Yes. All substitute parts listed (SZ1SMB5940BT3G, 1SMB5940BT3G, and SMBJ5367B-TP) are automotive-grade components with AEC-Q101 qualification, matching the main part's automotive qualification status.

Q: Do all parts have the same package and mounting type?

A: Yes. All parts use DO-214AA (SMB) package with surface mount technology. Physical footprint and PCB layout compatibility are identical across all listed parts.

Q: What is the significance of MSL 1 (Unlimited) rating?

A: MSL 1 (Unlimited) indicates unlimited shelf life without moisture baking requirements. All listed parts carry this rating, eliminating moisture sensitivity concerns during storage and handling.

Q: Are all parts ROHS3 compliant?

A: Yes. The main part and all substitute parts are ROHS3 compliant, meeting environmental and regulatory requirements for lead-free manufacturing and hazardous substance restrictions.