1SMB5940B-13 Equivalent & Substitute Parts

Part Overview

The 1SMB5940B-13 is a Zener diode rated at 43 V nominal voltage with 3 W maximum power dissipation in a surface mount SMB (DO-214AA) package. Manufactured by Diodes Incorporated, this component is classified as Active and RoHS3 compliant. Alternative part numbers become necessary when the primary manufacturer part is unavailable, when supply chain optimization is required, or when design flexibility across qualified manufacturers is needed while maintaining identical electrical and mechanical specifications.

Key Parameters

Parameter	Value	Unit
Voltage - Zener (Nom)	43	V
Tolerance	±5	%
Power - Max	3	W
Impedance (Max)	53	Ohms
Current - Reverse Leakage @ Vr	1	µA @ 32.7 V
Voltage - Forward (Vf) (Max) @ If	1.5	V @ 200 mA
Operating Temperature Range	-65 to 150	°C
Package / Case	DO-214AA, SMB	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitution of Zener diodes is determined by strict equivalence across electrical and mechanical parameters. The following criteria establish valid substitution:

Critical Matching Parameters:

Zener voltage (Vz): 43 V nominal
Tolerance: ±5%
Maximum power dissipation: 3 W
Maximum impedance (Zzt): 53 Ohms
Reverse leakage current: 1 µA @ 32.7 V
Forward voltage: 1.5 V @ 200 mA
Operating temperature range: -65°C to 150°C
Package type: DO-214AA (SMB)
Mounting configuration: Surface Mount

All substitute parts listed maintain identical values across these parameters, ensuring direct functional and mechanical compatibility without circuit redesign or thermal re-evaluation.

Parameter Comparison

Parameter	1SMB5940B-13 (Diodes Inc.)	1SMB5940BT3G (onsemi)	SZ1SMB5940BT3G (onsemi)
Voltage - Zener (Nom)	43 V	43 V	43 V
Tolerance	±5%	±5%	±5%
Power - Max	3 W	3 W	3 W
Impedance (Max)	53 Ohms	53 Ohms	53 Ohms
Current - Reverse Leakage @ Vr	1 µA @ 32.7 V	1 µA @ 32.7 V	1 µA @ 32.7 V
Voltage - Forward (Vf) (Max) @ If	1.5 V @ 200 mA	1.5 V @ 200 mA	1.5 V @ 200 mA
Operating Temperature	-65°C ~ 150°C	-65°C ~ 150°C	-65°C ~ 150°C
Package / Case	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB
Mounting Type	Surface Mount	Surface Mount	Surface Mount
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
Product Status	Active	Active	Active
REACH Status	REACH Unaffected	REACH Unaffected	REACH Unaffected

Engineering Selection Recommendations

1SMB5940BT3G (onsemi): This part is a direct manufacturer equivalent to the primary 1SMB5940B-13. All electrical parameters, thermal characteristics, and mechanical specifications are identical. Both components maintain Active product status and full RoHS3 compliance. Selection of this substitute is appropriate for supply chain continuity or multi-source procurement strategies.

SZ1SMB5940BT3G (onsemi): This part maintains identical electrical and mechanical specifications to the primary component. The distinction is automotive-grade qualification under AEC-Q101 standard. This variant is suitable for applications requiring automotive-level reliability and traceability. The AEC-Q101 qualification does not alter the core electrical parameters but indicates enhanced manufacturing process controls and documentation requirements specific to automotive supply chains.

All three parts are suitable for direct substitution based on parametric equivalence. Selection between them depends on supply availability, procurement source preferences, and application-specific qualification requirements rather than electrical or thermal performance differences.

Frequently Asked Questions (FAQ)

Q: Can 1SMB5940BT3G replace 1SMB5940B-13 in existing designs?

A: Yes. Both parts are parametrically equivalent across all electrical specifications, thermal ratings, and mechanical dimensions. No circuit modifications or thermal analysis updates are required.

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

A: Both parts are electrically and mechanically identical. The SZ1SMB5940BT3G variant carries AEC-Q101 automotive qualification, indicating compliance with automotive industry reliability and traceability standards. Selection depends on application requirements and supply chain specifications.

Q: Are all three parts in the same package?

A: Yes. All three parts use the DO-214AA (SMB) surface mount package with identical footprint and thermal characteristics.

Q: Do these parts have different moisture sensitivity requirements?

A: No. All three parts are classified as MSL 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.

Q: Can these parts be used interchangeably on the same PCB assembly?

A: Yes. Identical package type, pin configuration, and electrical specifications ensure direct interchangeability without PCB redesign or assembly process changes.

Q: Are all parts RoHS3 compliant?

A: Yes. All three parts meet ROHS3 compliance requirements and are REACH Unaffected.

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