SMAJ15A-13 Equivalent & Substitute Parts

Part Overview

The SMAJ15A-13 is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Diodes Incorporated in DO-214AC (SMA) surface mount package. This component is designed for general-purpose transient voltage suppression with a 15V reverse standoff voltage and 24.4V maximum clamping voltage at peak pulse current. The part is currently discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives from active manufacturers to maintain design continuity and ensure supply chain availability.

Substiute Parts

SMAJ15A-13

Diodes IncorporatedIn Stock: 7734SMAJ15A-13 Datasheet

Current PartRFQ

SMAJ15A-13-F

Diodes IncorporatedIn Stock: 20148SMAJ15A-13-F Datasheet

DirectRFQ

SMAJ15A

EVVO SemiIn Stock: 85255SMAJ15A Datasheet

DirectRFQ

SMAJ15A

EVVO SemiIn Stock: 85255SMAJ15A Datasheet

DirectRFQ

PTVS15VS1UR,115

Nexperia USA Inc.In Stock: 18837PTVS15VS1UR,115 Datasheet

MFR RecommendedRFQ

SM4T18AY

STMicroelectronicsIn Stock: 3186SM4T18AY Datasheet

MFR RecommendedRFQ

SMA6J15A-TP

Micro Commercial CoIn Stock: 1623SMA6J15A-TP Datasheet

MFR RecommendedRFQ

SMA6J15A-TR

STMicroelectronicsIn Stock: 1415SMA6J15A-TR Datasheet

MFR RecommendedRFQ

SMA6L15A

Littelfuse Inc.In Stock: 2244SMA6L15A Datasheet

MFR RecommendedRFQ

SMAJ15A-TR

STMicroelectronicsIn Stock: 74099SMAJ15A-TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMAJ15A-13 is determined by the following critical parameters:

Mandatory Matching Parameters:

• Voltage - Reverse Standoff (Typ): 15V
• Voltage - Breakdown (Min): 16.7V
• Package / Case: DO-214AC, SMA (or mechanically compatible alternative)
• Mounting Type: Surface Mount
• Type: Zener, Unidirectional

Allowable Variation Parameters:

• Voltage - Clamping (Max) @ Ipp: 24.4V nominal (variations within typical device tolerance acceptable)
• Current - Peak Pulse: 16.4A minimum (higher values acceptable)
• Power - Peak Pulse: 400W minimum (higher values acceptable)
• Operating Temperature: -55°C ~ 150°C minimum range (extended ranges acceptable)
• RoHS Status: ROHS3 Compliant preferred for new designs
• Product Status: Active preferred for supply continuity

Substitute parts must maintain electrical equivalence across the critical voltage parameters while accommodating mechanical and thermal specifications of the application circuit.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: SMAJ15A-13-F (Diodes Incorporated)

This part is the direct successor to the discontinued SMAJ15A-13, offering identical electrical specifications and package configuration. The only difference is ROHS3 compliance status, making it the optimal choice for design continuity. Active product status ensures long-term supply availability.

Secondary Recommendation: SMAJ15A (EVVO Semi)

Electrically equivalent with extended operating temperature range (-65°C ~ 150°C). ROHS3 compliant and active status. Suitable for applications requiring lower temperature operation. High inventory availability (85,200 pcs) supports supply chain stability.

Alternative for Compact Designs: PTVS15VS1UR,115 (Nexperia USA Inc.)

Maintains identical electrical specifications in SOD-123W package, offering smaller footprint than SMA. AEC-Q101 automotive qualification provides additional reliability assurance. Suitable only if PCB layout permits package change.

Higher Current Capability Options:

SMA6J15A-TP (Micro Commercial Co), SMA6J15A-TR (STMicroelectronics), and SMAJ15A-TR (STMicroelectronics) provide increased peak pulse current ratings (24.6A to 123A) and higher power dissipation (600W). These are suitable for applications requiring enhanced transient suppression capability. Clamping voltage variations (27.7V to 32.5V) remain within acceptable tolerance for 15V standoff applications.

Mechanical Compatibility Consideration: SMA6L15A (Littelfuse Inc.)

DO-221AC package with flat leads differs mechanically from standard SMA. Verify PCB footprint compatibility before selection. Extended temperature range (-65°C ~ 150°C) and higher power rating (600W) available.

All recommended substitutes maintain ROHS3 compliance and active product status, ensuring regulatory compliance and supply continuity.

Frequently Asked Questions (FAQ)

Q: Can SMAJ15A-13 be directly replaced with SMAJ15A-13-F?

A: Yes. SMAJ15A-13-F is the direct equivalent with identical electrical and mechanical specifications. The primary difference is ROHS3 compliance. No circuit modifications are required.

Q: What is the significance of the clamping voltage variation between substitute parts?

A: Clamping voltage determines the maximum voltage spike suppressed at the device terminals. The original SMAJ15A-13 specifies 24.4V maximum clamping. Substitutes with higher clamping voltages (27.7V to 32.5V) provide less aggressive suppression but remain functionally acceptable for 15V standoff applications. Lower clamping voltages are not acceptable. Verify circuit tolerance for peak voltage before selecting higher-clamping alternatives.

Q: Are package changes between SMA and SOD-123W interchangeable?

A: No. SMA (DO-214AC) and SOD-123W are different physical packages. PTVS15VS1UR,115 in SOD-123W requires PCB footprint redesign. Verify layout compatibility before substitution.

Q: What does the current rating difference (16.4A vs. 24.6A vs. 71A) mean for substitution?

A: Higher current ratings indicate greater transient suppression capability. Parts with higher ratings (SMA6J15A-TP at 24.6A, SM4T18AY at 71A) can suppress larger transient events without degradation. They are suitable replacements for the original 16.4A part. Lower current ratings are not acceptable.

Q: Is RoHS compliance mandatory for substitution?

A: RoHS compliance depends on application and regulatory requirements. The original SMAJ15A-13 is RoHS non-compliant. All active substitutes are ROHS3 compliant. For new designs and regulated applications, ROHS3 compliance is required. For legacy systems, non-compliant parts may remain acceptable if regulatory exemptions apply.

Q: Can I use STMicroelectronics TRANSIL™ series parts as substitutes?

A: Yes. SM4T18AY and SMAJ15A-TR (both STMicroelectronics TRANSIL™ series) meet the 15V standoff and 16.7V breakdown requirements. Higher clamping voltages and current ratings are acceptable for applications tolerating increased suppression capability. Verify circuit design margins before selection.

Q: What is the difference between operating temperature specifications (TJ vs. TA)?

A: TJ indicates junction temperature; TA indicates ambient temperature. Both specifications define safe operating ranges. Verify thermal design of the application to ensure selected part operates within specified limits under worst-case conditions.

Q: Is automotive qualification (AEC-Q101) required for my application?

A: AEC-Q101 qualification is required only for automotive applications. PTVS15VS1UR,115 carries this qualification. For non-automotive applications, qualification is not a substitution requirement.