1SMB12AT3 Equivalent & Substitute Parts

Part Overview

The 1SMB12AT3 is a transient voltage suppressor (TVS) diode manufactured by onsemi, rated for 12V reverse standoff voltage with a 19.9V clamping voltage. This component is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. The part operates as a unidirectional Zener-type TVS diode in a surface mount package, designed for general-purpose transient voltage protection applications.

Substiute Parts

1SMB12AT3

onsemiIn Stock: 37651SMB12AT3 Datasheet

Current PartRFQ

SMBJ12A

EVVO SemiIn Stock: 6384SMBJ12A Datasheet

DirectRFQ

SMBJ12A

EVVO SemiIn Stock: 6384SMBJ12A Datasheet

DirectRFQ

SMBJ12A-TR

STMicroelectronicsIn Stock: 3576SMBJ12A-TR Datasheet

DirectRFQ

SMBJ12A/54

Vishay General Semiconductor - Diodes DivisionIn Stock: 759SMBJ12A/54 Datasheet

DirectRFQ

PTVS12VP1UP,115

NXP SemiconductorsIn Stock: 165978PTVS12VP1UP,115 Datasheet

SimilarRFQ

SMBJ12A-TP

Micro Commercial CoIn Stock: 3478SMBJ12A-TP Datasheet

SimilarRFQ

TV06B120JB-G

Comchip TechnologyIn Stock: 1110TV06B120JB-G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 1SMB12AT3 is determined by the following critical electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 12V
• Voltage - Clamping (Max) @ Ipp: 19.9V
• Type: Zener, Unidirectional
• Mounting Type: Surface Mount
• Package / Case: DO-214AC or DO-214AA (SMB/SMA variants)
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

Substitute parts must match these parameters exactly. Parts are grouped as direct substitutes (identical electrical and mechanical specifications) or similar substitutes (functionally equivalent with minor package or manufacturer variations).

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Recommended Priority)

SMBJ12A-TR (STMicroelectronics) and SMBJ12A-TP (Micro Commercial Co) are the primary recommended substitutes. Both are active products with ROHS3 compliance, matching the critical electrical parameters of 12V reverse standoff and 19.9V clamping voltage. SMBJ12A-TR offers 31A peak pulse current in DO-214AA (SMB) package, while SMBJ12A-TP provides 30.2A in the same package with extended operating temperature range (-55°C to 175°C).

SMBJ12A (EVVO Semi) is functionally equivalent with 30.2A peak pulse current but uses DO-214AC (SMA) package, requiring PCB layout adjustment from the original SMB footprint.

Alternative Substitutes

SMBJ12A/54 (Vishay General Semiconductor) matches electrical specifications and package type but retains RoHS non-compliant status, limiting use in regulated applications.

TV06B120JB-G (Comchip Technology) is a bidirectional variant with equivalent electrical ratings (30.15A peak pulse current) in DO-214AA (SMB) package. This part is suitable only if bidirectional transient protection is acceptable for the application.

PTVS12VP1UP,115 (NXP Semiconductors) is listed as a similar substitute but lacks detailed electrical parameter specification in available documentation.

Compliance Considerations

For new designs requiring RoHS3 compliance, select SMBJ12A-TR, SMBJ12A-TP, or TV06B120JB-G. For legacy applications where RoHS compliance is not mandated, SMBJ12A/54 remains functionally compatible.

Frequently Asked Questions (FAQ)

Q: Can SMBJ12A (EVVO Semi) replace 1SMB12AT3 directly on the PCB?

A: SMBJ12A matches all critical electrical parameters but uses DO-214AC (SMA) package instead of SMB. This requires PCB footprint modification. If SMB package is mandatory, select SMBJ12A-TR or SMBJ12A-TP instead.

Q: What is the difference between SMBJ12A-TR and SMBJ12A-TP?

A: Both are functionally equivalent with 12V reverse standoff and 19.9V clamping voltage. SMBJ12A-TR (STMicroelectronics) operates from -55°C to 150°C, while SMBJ12A-TP (Micro Commercial Co) extends to -55°C to 175°C. SMBJ12A-TP offers wider temperature range for demanding environments.

Q: Is TV06B120JB-G suitable as a direct replacement?

A: TV06B120JB-G is bidirectional, whereas 1SMB12AT3 is unidirectional. Bidirectional operation provides protection in both directions but may introduce unwanted clamping in single-direction applications. Verify application requirements before substitution.

Q: Why is 1SMB12AT3 marked as obsolete?

A: Obsolescence indicates the manufacturer has discontinued production. Active alternatives with identical or superior specifications are available from multiple manufacturers, making transition to current products necessary for supply chain continuity.

Q: Does RoHS compliance matter for my application?

A: RoHS3 compliance is mandatory for products sold in the European Union and many regulated markets. If your application is subject to these regulations, select SMBJ12A-TR, SMBJ12A-TP, or TV06B120JB-G. For non-regulated applications, RoHS non-compliant parts remain functionally acceptable.

Q: What is the significance of peak pulse current ratings (30.2A vs 31A)?

A: Peak pulse current indicates the maximum transient current the diode can suppress. SMBJ12A-TR at 31A provides marginally higher transient handling capacity than SMBJ12A at 30.2A. Both are suitable for general-purpose applications; selection depends on specific transient energy requirements.