SMBJ78E3/TR13 Equivalent & Substitute Parts

Part Overview

The SMBJ78E3/TR13 is a unidirectional transient voltage suppressor (TVS) diode manufactured by Microchip Technology, classified as a Zener-type device in the SMBJ series. This surface-mount component operates within a reverse standoff voltage of 78V and provides clamping protection at 139V maximum, with a peak pulse current capacity of 4.3A. The device is active in production status and designed for general-purpose transient suppression applications. Substitute parts become necessary when primary inventory is depleted, when supply chain alternatives are required, or when equivalent performance characteristics meet application requirements while sourcing from alternative manufacturers.

Substiute Parts

SMBJ78E3/TR13

Microchip TechnologyIn Stock: 708SMBJ78E3/TR13 Datasheet

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SMBJ78A

MDDIn Stock: 9439SMBJ78A Datasheet

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SMBJ78A

MDDIn Stock: 9439SMBJ78A Datasheet

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SMBJ78A

MDDIn Stock: 9439SMBJ78A Datasheet

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SMBJ78A-13-F

Diodes IncorporatedIn Stock: 8706SMBJ78A-13-F Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Equivalent and substitute parts for the SMBJ78E3/TR13 are determined by matching the following critical electrical and mechanical parameters:

Primary Matching Criteria:

• Voltage - Reverse Standoff (Typ): 78V
• Voltage - Breakdown (Min): 86.7V
• Package / Case: DO-214AA, SMB (Surface Mount)
• Unidirectional Channels: 1
• Mounting Type: Surface Mount
• Compliance: ROHS3 Compliant, REACH Unaffected

Secondary Parameters for Compatibility:

• Voltage - Clamping (Max) @ Ipp: tolerance within application circuit design
• Current - Peak Pulse (10/1000µs): minimum 4.3A or greater
• Power - Peak Pulse: 600W minimum
• Product Status: Active
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

Substitute parts SMBJ78A (MDD) and SMBJ78A-13-F (Diodes Incorporated) are classified as equivalent because they maintain identical reverse standoff voltage, breakdown voltage, package configuration, and compliance certifications. Variations in clamping voltage (126V versus 139V) and peak pulse current (4.7A to 4.8A versus 4.3A) remain within acceptable parameters for general-purpose transient suppression applications where the primary circuit voltage protection requirement is the 78V standoff specification.

Parameter Comparison

Engineering Selection Recommendations

Selection between SMBJ78E3/TR13 and equivalent substitute parts is based on the following engineering criteria:

SMBJ78E3/TR13 (Microchip Technology): Primary specification choice when maximum clamping voltage tolerance of 139V is required. Extended lower temperature operating range (-65°C minimum) is necessary for applications in extreme cold environments. Microchip sourcing is preferred when existing supply relationships or quality assurance protocols favor this manufacturer.

SMBJ78A (MDD): Substitute option with improved peak pulse current capacity (4.8A versus 4.3A) and reduced maximum clamping voltage (126V). Operating temperature minimum of -50°C is suitable for standard industrial and commercial applications. High current capacity advantage applies to circuits requiring maximum transient energy absorption at the 78V protection level. All compliance certifications (ROHS3, REACH Unaffected) are equivalent.

SMBJ78A-13-F (Diodes Incorporated): Substitute option combining improved peak pulse current (4.7A) with reduced clamping voltage (126V) and extended lower temperature range (-55°C). Diodes Incorporated sourcing is preferred for supply chain diversification or when existing qualification history with this manufacturer is established. All compliance certifications are equivalent to the primary part.

All three variants maintain identical 78V reverse standoff voltage, 86.7V minimum breakdown voltage, DO-214AA/SMB surface-mount packaging, and ROHS3/REACH compliance status. Selection is driven by inventory availability, supply chain strategy, and application-specific temperature or clamping voltage constraints.

Frequently Asked Questions (FAQ)

Q: Can SMBJ78A replace SMBJ78E3/TR13 directly without circuit redesign?

A: SMBJ78A is electrically compatible when the application circuit tolerates a maximum clamping voltage of 126V instead of 139V. Both devices maintain the same 78V reverse standoff voltage and 86.7V breakdown voltage, which determine overvoltage protection thresholds. The improved peak pulse current (4.8A versus 4.3A) is beneficial in transient suppression applications. Direct PCB substitution is possible due to identical DO-214AA/SMB package geometry.

Q: What is the impact of different clamping voltages (139V versus 126V)?

A: The clamping voltage maximum is the peak voltage the device clamps transient events to during protection operation. Lower clamping voltage (126V) provides slightly tighter voltage regulation during transient suppression but requires verification that downstream circuit components rated for 139V maximum can operate at 126V clamped levels. For most general-purpose applications, 126V clamping is acceptable and advantageous for component protection margin.

Q: Are SMBJ78A and SMBJ78A-13-F interchangeable?

A: Both SMBJ78A variants (MDD and Diodes Incorporated) are electrically and mechanically equivalent. The primary differences are manufacturer source and minor operating temperature range variations (-50°C to -55°C minimum). Selection between these two SMBJ78A options is determined by supply chain availability and manufacturer preference without circuit impact.

Q: Does operating temperature range affect part selection?

A: Operating temperature range affects part selection only when the application circuit operates outside standard industrial temperature limits. SMBJ78E3/TR13 supports -65°C to 150°C, enabling use in extreme cold environments. SMBJ78A-13-F (-55°C to 150°C) and SMBJ78A (-50°C to 150°C) are suitable for standard commercial and industrial temperature ranges. Verify application minimum operating temperature against part specifications before selection.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. SMBJ78E3/TR13, SMBJ78A (MDD), and SMBJ78A-13-F (Diodes Incorporated) are all ROHS3 Compliant with MSL rating of 1 (Unlimited) and REACH Unaffected status, meeting current regulatory requirements for electronic components.

Q: What determines the 78V reverse standoff voltage specification?

A: The 78V reverse standoff voltage is the maximum continuous reverse voltage the TVS diode sustains without conducting. All three parts maintain this specification, ensuring identical overvoltage protection trigger points and circuit voltage regulation thresholds. This parameter is the primary determinant for TVS diode substitution compatibility.