SMAJ40A-13 Equivalent & Substitute Parts

Part Overview

The SMAJ40A-13 is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Diodes Incorporated in SMA (DO-214AC) surface mount packaging. This component is designed for general-purpose transient voltage suppression with a 40V reverse standoff voltage and 64.5V maximum clamping voltage. The part is currently discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives from active product lines that maintain electrical and mechanical compatibility.

Substiute Parts

SMAJ40A-13

Diodes IncorporatedIn Stock: 1173SMAJ40A-13 Datasheet

Current PartRFQ

SMAJ40A-13-F

Diodes IncorporatedIn Stock: 21881SMAJ40A-13-F Datasheet

DirectRFQ

PTVS40VS1UR,115

Nexperia USA Inc.In Stock: 18781PTVS40VS1UR,115 Datasheet

MFR RecommendedRFQ

SM4T47AY

STMicroelectronicsIn Stock: 4476SM4T47AY Datasheet

MFR RecommendedRFQ

SMA6J40A-TR

STMicroelectronicsIn Stock: 5153SMA6J40A-TR Datasheet

MFR RecommendedRFQ

SMAJ40A

MDDIn Stock: 3492SMAJ40A Datasheet

MFR RecommendedRFQ

SMAJ40A

MDDIn Stock: 3492SMAJ40A Datasheet

MFR RecommendedRFQ

SMAJ40A-TP

Micro Commercial CoIn Stock: 10725SMAJ40A-TP Datasheet

MFR RecommendedRFQ

SMAJ40A-TR

STMicroelectronicsIn Stock: 40141SMAJ40A-TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMAJ40A-13 is determined by the following critical parameters:

• Reverse Standoff Voltage: Must be 40V (Typ)
• Breakdown Voltage: Must be minimum 44.4V
• Package / Case: Must be DO-214AC, SMA (surface mount)
• Mounting Type: Must be Surface Mount
• Diode Type: Must be Zener
• Unidirectional Channels: Must be 1

Substitute parts are grouped into two categories based on electrical performance:

Category A - Electrical Equivalents: Parts with identical clamping voltage (64.5V) and peak pulse current (6.2A), maintaining full functional equivalence.

Category B - Higher Performance Alternatives: Parts with the same standoff and breakdown voltages but higher clamping voltage and peak pulse current ratings, suitable for applications requiring enhanced transient suppression capability.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Same Package, Identical Electrical Performance)

SMAJ40A-13-F, SMAJ40A-TP, and SMAJ40A from MDD are direct functional equivalents with identical electrical specifications. All three are in active product status with ROHS3 compliance. SMAJ40A-13-F is the original manufacturer's (Diodes Incorporated) direct successor and maintains the same tape & reel packaging format. SMAJ40A-TP from Micro Commercial Co and SMAJ40A from MDD provide equivalent performance with broader temperature operating ranges (-55°C to 175°C and -50°C to 150°C respectively).

Higher Performance Alternatives (Same Package, Enhanced Ratings)

SMAJ40A-TR and SM4T47AY from STMicroelectronics, and SMA6J40A-TR also from STMicroelectronics, maintain the same 40V standoff voltage and DO-214AC SMA package but provide higher clamping voltage and peak pulse current. These parts are suitable for applications requiring enhanced transient suppression margin. SMAJ40A-TR and SM4T47AY both offer 84V clamping voltage with 27A peak pulse current. SMA6J40A-TR provides 73.6V clamping voltage with 48A peak pulse current and 600W peak pulse power, representing the highest performance option in the SMA package family.

Alternative Package Option

PTVS40VS1UR,115 from Nexperia USA Inc. provides identical electrical performance to the original part but in SOD-123W surface mount packaging. This option is suitable only if PCB layout and assembly equipment support SOD-123W components. The part carries AEC-Q101 automotive qualification.

Frequently Asked Questions (FAQ)

Q: Can SMAJ40A-13-F be used as a direct replacement for SMAJ40A-13?

A: Yes. SMAJ40A-13-F is the direct successor from Diodes Incorporated with identical electrical specifications (40V standoff, 64.5V clamping, 6.2A peak pulse current) and the same DO-214AC SMA package. The primary difference is product status (active vs. discontinued) and RoHS compliance (ROHS3 vs. non-compliant).

Q: What is the difference between SMAJ40A-13 and the higher-performance alternatives like SMAJ40A-TR?

A: Both maintain the same 40V reverse standoff voltage and DO-214AC SMA package, ensuring mechanical and circuit compatibility. However, SMAJ40A-TR provides higher clamping voltage (84V vs. 64.5V) and peak pulse current (27A vs. 6.2A). Use higher-performance alternatives only if your application requires enhanced transient suppression capability, as they may alter circuit behavior in sensitive applications.

Q: Can PTVS40VS1UR,115 replace SMAJ40A-13 in existing designs?

A: PTVS40VS1UR,115 provides identical electrical performance but uses SOD-123W packaging instead of DO-214AC SMA. Direct PCB substitution is not possible without layout modification. This option is viable only if your assembly process supports SOD-123W components and PCB footprints can be redesigned.

Q: Are all substitute parts RoHS compliant?

A: All active substitute parts listed are ROHS3 compliant. The original SMAJ40A-13 is RoHS non-compliant. If RoHS compliance is a design requirement, select from the active alternatives.

Q: Which substitute part should I select for a new design?

A: For direct electrical and mechanical equivalence, use SMAJ40A-13-F from Diodes Incorporated or SMAJ40A-TP from Micro Commercial Co. Both are in active production with full RoHS3 compliance and identical performance to the original part. For applications requiring enhanced transient suppression, evaluate SMAJ40A-TR or SMA6J40A-TR from STMicroelectronics.