SMCJ78A-13 Equivalent & Substitute Parts

Part Overview

The SMCJ78A-13 is a unidirectional 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, 126V maximum clamping voltage, and 1500W peak pulse power rating in the DO-214AB (SMC) package.

The SMCJ78A-13 is currently discontinued at DiGi Electronics and carries RoHS non-compliant status. Due to its discontinued product status and regulatory compliance requirements in modern supply chains, equivalent substitute parts with active product status and RoHS3 compliance are necessary for new designs and ongoing production requirements.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	78	V
Voltage - Breakdown (Min)	86.7	V
Voltage - Clamping (Max) @ Ipp	126	V
Current - Peak Pulse (10/1000µs)	11.4	A
Power - Peak Pulse	1500	W
Operating Temperature Range	-55 to 150	°C
Package / Case	DO-214AB, SMC	—
Mounting Type	Surface Mount	—
Type	Zener	—
Unidirectional Channels	1	—

Substitute Part Grouping Explanation

Substitute parts for the SMCJ78A-13 are grouped based on strict electrical and mechanical compatibility criteria:

Primary Substitution Criteria:

Voltage - Reverse Standoff (Typ): 78V
Voltage - Breakdown (Min): 86.7V
Voltage - Clamping (Max) @ Ipp: 126V
Package / Case: DO-214AB, SMC
Mounting Type: Surface Mount
Unidirectional Channels: 1
Type: Zener

Grouping Logic:

Group 1: Direct Electrical & Mechanical Equivalents (1500W Class) Parts meeting all primary criteria with identical peak pulse power rating (1500W) and peak pulse current within acceptable tolerance:

SMCJ78A (MDD) — 11.9A peak pulse current
SMCJ78A-TP (Micro Commercial Co) — 11.9A peak pulse current

Group 2: Higher Power Rated Alternatives (3000W–5000W Class) Parts meeting all primary voltage and package criteria but with elevated peak pulse power ratings and corresponding higher peak pulse currents. These provide enhanced transient protection capability:

SMDJ78A (Alpha & Omega Semiconductor Inc.) — 3000W, 23.9A peak pulse current
5.0SMDJ78A (Taiwan Semiconductor Corporation) — 5000W, 39.7A peak pulse current
5.0SMDJ78A-T7 (Littelfuse Inc.) — 5000W, 39.7A peak pulse current

All substitute parts maintain the same voltage protection window (78V standoff, 126V clamp) and surface-mount DO-214AB package compatibility.

Parameter Comparison

Manufacturer Part Number	Manufacturer	Voltage - Reverse Standoff (Typ) [V]	Voltage - Breakdown (Min) [V]	Voltage - Clamping (Max) @ Ipp [V]	Current - Peak Pulse (10/1000µs) [A]	Power - Peak Pulse [W]	Operating Temperature [°C]	Product Status	RoHS Status
SMCJ78A-13	Diodes Incorporated	78	86.7	126	11.4	1500	-55 to 150	Discontinued	Non-compliant
SMCJ78A	MDD	78	86.7	126	11.9	1500	-50 to 150	Active	ROHS3 Compliant
SMCJ78A-TP	Micro Commercial Co	78	86.7	126	11.9	1500	-55 to 175	Active	ROHS3 Compliant
SMDJ78A	Alpha & Omega Semiconductor Inc.	78	86.7	126	23.9	3000	-55 to 150	Active	ROHS3 Compliant
5.0SMDJ78A	Taiwan Semiconductor Corporation	78	86.7	126	39.7	5000	-55 to 175	Active	ROHS3 Compliant
5.0SMDJ78A-T7	Littelfuse Inc.	78	86.7	126	39.7	5000	-65 to 150	Active	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (1500W Class): SMCJ78A (MDD) and SMCJ78A-TP (Micro Commercial Co) are functionally equivalent to the SMCJ78A-13. Both are active products with ROHS3 compliance and identical power ratings. SMCJ78A-TP offers an extended upper operating temperature limit of 175°C compared to 150°C for the MDD variant, providing additional thermal margin in high-temperature environments.

For Enhanced Protection (3000W–5000W Class): SMDJ78A, 5.0SMDJ78A, and 5.0SMDJ78A-T7 provide higher transient energy absorption capability while maintaining identical voltage protection parameters. These are suitable for applications requiring greater surge current handling or where circuit protection margins must be increased. All three are active products with ROHS3 compliance.

Compliance Considerations: All substitute parts carry ROHS3 compliance status, addressing the regulatory gap of the discontinued SMCJ78A-13. Selection should prioritize active product status and compliance certifications for supply chain continuity and regulatory adherence in new designs.

Frequently Asked Questions (FAQ)

Q: Can SMCJ78A-13 be directly replaced with SMCJ78A or SMCJ78A-TP? A: Yes. Both SMCJ78A (MDD) and SMCJ78A-TP (Micro Commercial Co) maintain identical voltage protection parameters (78V standoff, 126V clamp), peak pulse power rating (1500W), and DO-214AB package compatibility. The primary differences are manufacturer, product status (both active), and RoHS compliance (both ROHS3 compliant). SMCJ78A-TP offers extended temperature range to 175°C.

Q: What is the difference between 1500W and higher-power rated substitutes? A: Higher-power variants (SMDJ78A at 3000W, 5.0SMDJ78A and 5.0SMDJ78A-T7 at 5000W) maintain identical voltage protection windows but handle greater transient surge currents. The voltage clamping behavior remains the same; the increased power rating reflects higher peak pulse current capacity. Selection depends on circuit transient energy requirements.

Q: Are all substitute parts in the same package? A: Yes. All substitute parts use the DO-214AB (SMC) surface-mount package, ensuring mechanical and footprint compatibility with the original SMCJ78A-13 design.

Q: Why is RoHS compliance important for this substitution? A: The original SMCJ78A-13 is RoHS non-compliant and discontinued. Modern supply chains and regulatory requirements mandate RoHS3 compliance. All listed substitutes meet this requirement, ensuring long-term availability and regulatory adherence.

Q: Can higher-power rated parts be used in place of the 1500W original? A: Yes. Higher-power rated TVS diodes (SMDJ78A, 5.0SMDJ78A, 5.0SMDJ78A-T7) provide equivalent voltage protection with enhanced transient energy absorption. They are backward-compatible in applications where the original 1500W rating was adequate, offering improved protection margins.

Q: What temperature range should I consider for my application? A: The original SMCJ78A-13 operates from -55°C to 150°C. SMCJ78A-TP and 5.0SMDJ78A extend the upper limit to 175°C, while 5.0SMDJ78A-T7 extends the lower limit to -65°C. Select based on your application's thermal environment.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message