SMBJ78C Equivalent & Substitute Parts

Part Overview

The SMBJ78C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 78V reverse standoff voltage with a 132.3V maximum clamping voltage and 4.8A peak pulse current capability in a DO-214AA (SMB) package. The SMBJ78C is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement.

Substiute Parts

SMBJ78C

Littelfuse Inc.In Stock: 806SMBJ78C Datasheet

Current PartRFQ

SMBJ78CA

MeritekIn Stock: 4479SMBJ78CA Datasheet

MFR RecommendedRFQ

SMBJ78CA

MeritekIn Stock: 4479SMBJ78CA Datasheet

MFR RecommendedRFQ

SMBJ78CA

MeritekIn Stock: 4479SMBJ78CA Datasheet

MFR RecommendedRFQ

SMBJ78CA-M3/5B

Vishay General Semiconductor - Diodes DivisionIn Stock: 999SMBJ78CA-M3/5B Datasheet

MFR RecommendedRFQ

TV06B780JB-HF

Comchip TechnologyIn Stock: 870TV06B780JB-HF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMBJ78C is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Voltage - Reverse Standoff (Typ): 78V
• Voltage - Clamping (Max) @ Ipp: Must not exceed 132.3V
• Current - Peak Pulse (10/1000µs): Minimum 4.76A
• Power - Peak Pulse: 600W
• Type: Zener diode, bidirectional, single channel

Mechanical Compatibility Criteria:

• Package / Case: DO-214AA (SMB)
• Mounting Type: Surface Mount
• Packaging: Tape & Reel (TR)

Compliance Requirements:

• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

All substitute parts listed maintain these core parameters within acceptable engineering tolerances for direct replacement in the SMBJ78C application circuit.

Parameter Comparison

Engineering Selection Recommendations

All three substitute parts—SMBJ78CA (Meritek), SMBJ78CA-M3/5B (Vishay), and TV06B780JB-HF (Comchip)—are active products with ROHS3 compliance and MSL 1 rating, providing long-term availability and regulatory compliance advantages over the obsolete SMBJ78C.

The SMBJ78CA-M3/5B (Vishay TransZorb® series) and TV06B780JB-HF (Comchip) both maintain the 4.8A peak pulse current specification matching the original SMBJ78C. The SMBJ78CA variants (Meritek and Vishay) feature a reduced clamping voltage of 126V compared to the original 132.3V, representing improved transient suppression performance while remaining within acceptable circuit design margins for 78V standoff applications.

The Meritek SMBJ78CA option provides the highest inventory availability (4400 pcs) among active alternatives. The Vishay SMBJ78CA-M3/5B maintains full parameter alignment with the original specification and includes REACH compliance documentation.

Frequently Asked Questions (FAQ)

Q: Can SMBJ78CA be used as a direct replacement for SMBJ78C?

A: Yes. Both parts share identical reverse standoff voltage (78V), package (DO-214AA/SMB), mounting type (surface mount), and power rating (600W). The SMBJ78CA features a lower clamping voltage (126V vs. 132.3V), which provides improved overvoltage suppression performance in the same circuit application.

Q: What is the difference between SMBJ78CA and SMBJ78CA-M3/5B?

A: Both are 78V TVS diodes in DO-214AA packages with identical electrical specifications. SMBJ78CA-M3/5B is the Vishay TransZorb® branded variant with REACH compliance documentation. The "-M3/5B" suffix indicates Vishay's specific packaging and tape configuration. Functionally, they are equivalent for circuit design purposes.

Q: Why does TV06B780JB-HF have no specified operating temperature range?

A: The operating temperature specification was not provided in the component data. For applications requiring confirmed temperature performance, the Vishay SMBJ78CA-M3/5B (-55°C ~ 150°C) or Meritek SMBJ78CA (-55°C ~ 150°C) are recommended as they provide explicit temperature ratings.

Q: Is the reduced clamping voltage (126V vs. 132.3V) in substitute parts a concern?

A: No. The lower clamping voltage in SMBJ78CA variants represents improved transient suppression, clamping overvoltage events to a lower peak level. This is beneficial for circuit protection and does not create compatibility issues in applications designed for 78V standoff protection.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. SMBJ78CA (Meritek), SMBJ78CA-M3/5B (Vishay), and TV06B780JB-HF (Comchip) are all ROHS3 compliant with MSL 1 moisture sensitivity rating, meeting current regulatory requirements for electronic component procurement.

Q: Which substitute offers the best long-term availability?

A: SMBJ78CA (Meritek) currently has the highest inventory (4400 pcs new original in stock) and active product status, providing the strongest availability profile for ongoing procurement needs.