1SMB5945B-13 Equivalent & Substitute Parts

Part Overview

The 1SMB5945B-13 is a Zener diode rated at 68 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 complies with ROHS3 and REACH standards. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity for applications requiring 68 V Zener diodes with comparable electrical and mechanical characteristics.

Substiute Parts

1SMB5945B-13

Diodes IncorporatedIn Stock: 33311SMB5945B-13 Datasheet

Current PartRFQ

SMBJ5373B-TP

Micro Commercial CoIn Stock: 4110SMBJ5373B-TP Datasheet

MFR RecommendedRFQ

1SMB5945BT3G

onsemiIn Stock: 209251SMB5945BT3G Datasheet

Parametric EquivalentRFQ

SZ1SMB5945BT3G

onsemiIn Stock: 5213SZ1SMB5945BT3G Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 1SMB5945B-13 are classified into two categories based on electrical and mechanical compatibility:

Parametric Equivalents share identical or equivalent electrical specifications:

• Nominal Zener voltage: 68 V
• Tolerance: ±5%
• Power rating: 3 W
• Impedance (Max): 120 Ohms
• Reverse leakage current: 1 µA @ 51.7 V
• Forward voltage: 1.5 V @ 200 mA
• Operating temperature range: -65°C to 150°C
• Package: DO-214AA, SMB (Surface Mount)
• RoHS3 compliance and MSL 1 rating

Manufacturer Recommended Substitute offers enhanced performance characteristics:

• Nominal Zener voltage: 68 V (identical)
• Tolerance: ±5% (identical)
• Power rating: 5 W (higher capability)
• Impedance (Max): 44 Ohms (lower impedance)
• Reverse leakage current: 500 nA @ 51.7 V (lower leakage)
• Forward voltage: 1.2 V @ 1 mA (lower forward drop)
• Operating temperature range: -55°C to 150°C (narrower range)
• Package: DO-214AA, SMB (identical)
• RoHS3 compliance and MSL 1 rating

All substitute parts maintain Surface Mount SMB packaging and are Active products with full regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

1SMB5945BT3G (onsemi) and SZ1SMB5945BT3G (onsemi, AEC-Q101) are direct parametric equivalents to the 1SMB5945B-13. Both parts maintain identical electrical specifications across all critical parameters: 68 V nominal Zener voltage, ±5% tolerance, 3 W power rating, 120 Ohms maximum impedance, and -65°C to 150°C operating temperature range. Both are ROHS3 compliant with MSL 1 rating. The SZ1SMB5945BT3G variant includes AEC-Q101 automotive qualification, making it suitable for automotive applications requiring enhanced reliability standards.

SMBJ5373B-TP (Micro Commercial Co) is classified as a manufacturer-recommended substitute with enhanced performance characteristics. While maintaining the same 68 V nominal voltage, ±5% tolerance, and SMB package, this part offers higher power dissipation (5 W versus 3 W), lower impedance (44 Ohms versus 120 Ohms), and lower reverse leakage current (500 nA versus 1 µA). The operating temperature range is -55°C to 150°C, which is narrower at the lower end. This part is suitable for applications where higher power handling or lower impedance characteristics provide design advantages.

All substitute parts are Active products with current inventory availability and full regulatory compliance. Selection should be based on specific application requirements regarding power dissipation, impedance characteristics, temperature range, and automotive qualification needs.

Frequently Asked Questions (FAQ)

Q: Can 1SMB5945BT3G be used as a direct replacement for 1SMB5945B-13?

A: Yes. The 1SMB5945BT3G is a parametric equivalent with identical electrical specifications: 68 V nominal Zener voltage, ±5% tolerance, 3 W power rating, 120 Ohms impedance, 1 µA reverse leakage, and -65°C to 150°C operating temperature. Both use the DO-214AA SMB package and are ROHS3 compliant with MSL 1 rating.

Q: What is the difference between 1SMB5945BT3G and SZ1SMB5945BT3G?

A: Both parts are parametric equivalents with identical electrical specifications. The SZ1SMB5945BT3G includes AEC-Q101 automotive qualification, making it suitable for automotive applications requiring enhanced reliability and qualification standards. The base electrical performance is identical.

Q: When should SMBJ5373B-TP be selected instead of the original part?

A: SMBJ5373B-TP is a manufacturer-recommended substitute offering enhanced performance: 5 W power rating (versus 3 W), 44 Ohms impedance (versus 120 Ohms), and 500 nA reverse leakage (versus 1 µA). Select this part when applications require higher power dissipation capability or lower impedance characteristics. The operating temperature range is -55°C to 150°C, which is narrower at the lower end.

Q: Are all substitute parts compatible with the same PCB footprint?

A: Yes. All substitute parts use the DO-214AA SMB package with Surface Mount configuration, ensuring mechanical and footprint compatibility with the original 1SMB5945B-13.

Q: Do all substitute parts meet the same regulatory requirements?

A: Yes. All substitute parts are ROHS3 compliant, REACH unaffected, and carry MSL 1 (Unlimited) moisture sensitivity rating. The SZ1SMB5945BT3G additionally carries AEC-Q101 automotive qualification.

Q: What is the inventory status of substitute parts?

A: 1SMB5945BT3G has 20,864 pieces in stock. SZ1SMB5945BT3G has 5,200 pieces in stock. SMBJ5373B-TP has 4,100 pieces in stock. The original 1SMB5945B-13 has 3,257 pieces in stock.