SMAJ78A-13 Equivalent & Substitute Parts

Part Overview

The SMAJ78A-13 is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Diodes Incorporated, designed for general-purpose overvoltage protection in surface-mount applications. This component features a 78V reverse standoff voltage with 126V maximum clamping voltage and 2.2A peak pulse current capability in a DO-214AC (SMA) package.

The SMAJ78A-13 is currently discontinued at DiGi Electronics. Equivalent and substitute parts are available from alternative manufacturers that maintain the same electrical specifications and package form factor, ensuring direct functional replacement in existing designs.

Substiute Parts

SMAJ78A-13

Diodes IncorporatedIn Stock: 5147SMAJ78A-13 Datasheet

Current PartRFQ

SMAJ78A

MeritekIn Stock: 1389SMAJ78A Datasheet

DirectRFQ

SMAJ78A

MeritekIn Stock: 1389SMAJ78A Datasheet

DirectRFQ

SMAJ78A-TP

Micro Commercial CoIn Stock: 6050SMAJ78A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMAJ78A-13 is determined by strict equivalence in the following electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 78V
• Voltage - Breakdown (Min): 86.7V
• Voltage - Clamping (Max) @ Ipp: 126V
• Package / Case: DO-214AC (SMA)
• Mounting Type: Surface Mount
• Type: Zener, Unidirectional

Substitute parts must maintain identical voltage ratings and clamping characteristics to ensure proper overvoltage protection function. Peak pulse current and power dissipation may vary within the same voltage class, provided the substitute meets or exceeds the original specification. Package compatibility is mandatory for direct board-level replacement without layout modification.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts maintain electrical equivalence to the SMAJ78A-13 across all critical voltage and clamping parameters. Selection between alternatives is based on product availability, compliance requirements, and packaging format:

SMAJ78A (Meritek): Active product status with ROHS3 compliance. Peak pulse current specification of 3.17A exceeds the original 2.2A requirement, providing additional margin for transient suppression. Suitable for applications requiring RoHS-compliant components with enhanced current handling.

SMAJ78A-TP (Micro Commercial Co): Active product status with ROHS3 compliance and manufacturer-recommended designation. Matches the original 2.2A peak pulse current specification. Extended operating temperature range to 175°C (TA) provides thermal margin. Available in Tape & Reel packaging for automated assembly processes. Recommended for high-volume production environments.

Both substitutes are electrically and mechanically compatible with the discontinued SMAJ78A-13 and require no circuit design modification.

Frequently Asked Questions (FAQ)

Q: Can SMAJ78A (Meritek) be used as a direct replacement for SMAJ78A-13?

A: Yes. Both parts share identical voltage ratings (78V standoff, 126V clamping) and DO-214AC (SMA) package specifications. The Meritek variant features higher peak pulse current (3.17A vs. 2.2A), which is compatible with the original design. ROHS3 compliance is an additional benefit for regulated applications.

Q: What is the difference between SMAJ78A-TP and SMAJ78A-13?

A: The SMAJ78A-TP is electrically equivalent with identical voltage and current specifications. Primary differences are product status (active vs. discontinued), RoHS compliance (ROHS3 vs. non-compliant), extended operating temperature range (175°C vs. 150°C), and packaging format (Tape & Reel vs. bulk). No circuit modification is required for substitution.

Q: Does the higher peak pulse current in the Meritek part affect circuit compatibility?

A: No. The 3.17A specification in the Meritek SMAJ78A exceeds the original 2.2A requirement and maintains the same voltage clamping characteristics. This provides additional transient suppression capability without affecting circuit operation.

Q: Are both substitutes available in the same package?

A: Yes. Both SMAJ78A (Meritek) and SMAJ78A-TP (Micro Commercial Co) use the DO-214AC (SMA) surface-mount package, identical to the original SMAJ78A-13. Board-level compatibility is maintained without layout changes.

Q: Which substitute is recommended for new designs?

A: SMAJ78A-TP (Micro Commercial Co) is the manufacturer-recommended substitute. It provides active product status, ROHS3 compliance, extended temperature range, and Tape & Reel packaging suitable for automated manufacturing. The electrical specifications match the original design exactly.