1SMA24AT3 Equivalent & Substitute Parts

Part Overview

The 1SMA24AT3 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by onsemi, designed for general-purpose transient protection applications. This component features a 24V reverse standoff voltage with a 38.9V maximum clamping voltage and 10.3A peak pulse current capability in a surface-mount SMA (DO-214AC) package. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

1SMA24AT3

onsemiIn Stock: 13371SMA24AT3 Datasheet

Current PartRFQ

SMAJ24A

MDDIn Stock: 21161SMAJ24A Datasheet

DirectRFQ

SMAJ24A

MDDIn Stock: 21161SMAJ24A Datasheet

DirectRFQ

SMAJ24A-TR

STMicroelectronicsIn Stock: 9197SMAJ24A-TR Datasheet

DirectRFQ

P4SMAJ24A_R1_00001

Panjit International Inc.In Stock: 4562P4SMAJ24A_R1_00001 Datasheet

SimilarRFQ

PTVS24VS1UR,115

Nexperia USA Inc.In Stock: 18719PTVS24VS1UR,115 Datasheet

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SM4T28AY

STMicroelectronicsIn Stock: 15649SM4T28AY Datasheet

SimilarRFQ

SMA6J24A-E3/61

Vishay General Semiconductor - Diodes DivisionIn Stock: 879SMA6J24A-E3/61 Datasheet

SimilarRFQ

SMA6J24A-TP

Micro Commercial CoIn Stock: 19833SMA6J24A-TP Datasheet

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SMAJ24A-13-F

Diodes IncorporatedIn Stock: 3119SMAJ24A-13-F Datasheet

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SMAJ24AE3/TR13

Microchip TechnologyIn Stock: 1050SMAJ24AE3/TR13 Datasheet

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SMAJ24E3/TR13

Microchip TechnologyIn Stock: 945SMAJ24E3/TR13 Datasheet

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TV04A240J-G

Comchip TechnologyIn Stock: 1105TV04A240J-G Datasheet

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TV04A240J-HF

Comchip TechnologyIn Stock: 1011TV04A240J-HF Datasheet

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TV04A240JB-G

Comchip TechnologyIn Stock: 28670TV04A240JB-G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the 1SMA24AT3 is determined by the following critical parameters:

• Voltage - Reverse Standoff: 24V (exact match required)
• Voltage - Breakdown (Min): 26.7V (exact match required)
• Voltage - Clamping (Max) @ Ipp: 38.9V (primary electrical characteristic)
• Current - Peak Pulse (10/1000µs): 10.3A (minimum requirement)
• Power - Peak Pulse: 400W (minimum requirement)
• Package / Case: DO-214AC, SMA (mechanical compatibility)
• Mounting Type: Surface Mount (assembly compatibility)

Substitute parts are grouped into two categories:

Direct Equivalents (Identical Electrical Specifications): Parts with matching voltage ratings, clamping voltage, and peak pulse current specifications. These provide pin-for-pin and functional compatibility.

Compatible Alternatives (Enhanced Specifications): Parts with identical voltage ratings and package but higher peak pulse current or clamping voltage ratings. These provide superior transient protection capability while maintaining electrical compatibility within the 24V protection window.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Electrical Performance):

SMAJ24A (MDD), P4SMAJ24A_R1_00001 (Panjit International Inc.), SMAJ24A-13-F (Diodes Incorporated), and SMAJ24AE3/TR13 (Microchip Technology) provide electrical equivalence to the 1SMA24AT3. All substitute parts are active products with ROHS3 compliance, addressing the obsolescence and regulatory status of the original component. SMAJ24AE3/TR13 matches the original operating temperature range of -65°C to 150°C.

For Enhanced Protection (Higher Current Handling):

SMA6J24A-TP (Micro Commercial Co) and SMA6J24A-E3/61 (Vishay) offer increased peak pulse current ratings (15.4A and 80A respectively) while maintaining the 24V protection window. These are suitable for applications requiring higher transient energy absorption. SMA6J24A-E3/61 provides the highest peak pulse current (80A) and power dissipation (4kW), appropriate for demanding industrial or automotive applications.

For Alternative Package Consideration:

PTVS24VS1UR,115 (Nexperia USA Inc.) provides electrical equivalence in SOD-123W package format. This part is AEC-Q101 qualified for automotive applications and maintains identical voltage and current specifications. Select this option only if PCB layout accommodates the SOD-123W footprint.

For Enhanced Current Capability with Standard Package:

SMAJ24A-TR (STMicroelectronics) and SM4T28AY (STMicroelectronics) both feature 46A peak pulse current in the standard DO-214AC, SMA package. Both are TRANSIL™ series components with AEC-Q101 automotive qualification.

All recommended substitutes are currently active products with full RoHS3 compliance, ensuring long-term availability and regulatory alignment.

Frequently Asked Questions (FAQ)

Q: Can SMAJ24A-TR be used as a direct replacement for 1SMA24AT3?

A: SMAJ24A-TR is electrically compatible for the 24V protection window but features a higher clamping voltage (50V vs. 38.9V) and significantly higher peak pulse current (46A vs. 10.3A). It provides enhanced transient protection capability. Verify that the application circuit can tolerate the higher clamping voltage before substitution.

Q: What is the difference between parts with 38.9V clamping and 50V clamping?

A: The clamping voltage determines the maximum voltage the TVS diode allows across the protected circuit during a transient event. Lower clamping voltage (38.9V) provides tighter voltage regulation. Higher clamping voltage (50V) allows slightly higher transient voltages but may be necessary for applications with higher current transients. Select based on circuit protection requirements.

Q: Is PTVS24VS1UR,115 compatible with existing PCB layouts designed for SMA package?

A: No. PTVS24VS1UR,115 uses SOD-123W package, which has a different footprint than DO-214AC (SMA). PCB layout modification is required. Use this part only if the SOD-123W footprint is available or if the design can be revised.

Q: Why do some substitutes have higher peak pulse current ratings?

A: Higher peak pulse current ratings indicate greater transient energy handling capability. Parts like SMA6J24A-E3/61 (80A) are designed for applications with more severe transient events. They provide the same 24V protection window but with enhanced margin for high-energy transients.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All active substitute parts listed are ROHS3 compliant, addressing the RoHS non-compliant status of the obsolete 1SMA24AT3. This ensures regulatory compliance for new designs and procurement.

Q: Which substitute offers the closest match to the original 1SMA24AT3 specifications?

A: SMAJ24A (MDD), P4SMAJ24A_R1_00001 (Panjit), SMAJ24A-13-F (Diodes), and SMAJ24AE3/TR13 (Microchip) all provide identical electrical specifications (24V standoff, 26.7V breakdown, 38.9V clamping, 10.3A peak pulse). SMAJ24AE3/TR13 additionally matches the original -65°C to 150°C operating temperature range.

Q: Can higher-rated parts like SMA6J24A-E3/61 be used in applications designed for 1SMA24AT3?

A: Yes, with circuit verification. Higher-rated parts provide superior transient protection and are backward compatible for the 24V protection window. However, the higher clamping voltage (44.3V for SMA6J24A-E3/61) must be acceptable to the protected circuit. Confirm that downstream components tolerate this voltage level.

Q: What packaging options are available for 24V TVS diodes?

A: The primary package for these 24V TVS diodes is DO-214AC (SMA), used by most substitutes. PTVS24VS1UR,115 offers SOD-123W as an alternative. DO-214AC is the standard for general-purpose applications; SOD-123W is used in space-constrained designs.