SMBJ33 Transient Voltage Suppressor (TVS) Diode – Equivalent & Substitute Parts

Part Overview

The SMBJ33 is a unidirectional Zener transient voltage suppressor manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component operates with a 33V reverse standoff voltage and provides peak pulse power dissipation of 600W in a DO-214AA (SMB) package. The SMBJ33 is classified as obsolete, making identification of functionally equivalent active alternatives necessary for ongoing design support and procurement.

Key Parameters

Parameter	Value	Unit
Manufacturer Part Number	SMBJ33	—
Manufacturer	Littelfuse Inc.	—
Category	Transient Voltage Suppressors (TVS)	—
Type	Zener	—
Unidirectional Channels	1	—
Voltage – Reverse Standoff (Typ)	33	V
Voltage – Breakdown (Min)	34.79	V
Voltage – Clamping (Max) @ Ipp	55.97	V
Current – Peak Pulse (10/1000µs)	11.3	A
Power – Peak Pulse	600	W
Package / Case	DO-214AA, SMB	—
Mounting Type	Surface Mount	—
Operating Temperature	−65 to 150	°C (TJ)
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level (MSL)	1 (Unlimited)	—
Product Status	Obsolete	—

Substitute Part Grouping Explanation

Substitution of the SMBJ33 is determined by the following critical electrical and mechanical parameters:

Voltage – Reverse Standoff (Typ): 33V
Voltage – Clamping (Max) @ Ipp: Must not exceed 55.97V (original specification)
Current – Peak Pulse (10/1000µs): Minimum 11.3A
Power – Peak Pulse: Minimum 600W
Package / Case: DO-214AA, SMB (surface mount)
Mounting Type: Surface Mount
RoHS Status: ROHS3 Compliant
Moisture Sensitivity Level (MSL): 1 (Unlimited)

All identified substitute parts maintain the 33V reverse standoff voltage and DO-214AA SMB package footprint. Substitute parts are grouped into two categories based on peak pulse current and power dissipation capacity:

Group 1 (600W, 11.3A nominal): SMBJ33A (Good-Ark), SZ1SMB33AT3G (Littelfuse), SMBJ33A-13-F (Diodes Inc.), SMBJ33A-TP (Micro Commercial Co), TV06B330J-G (Comchip), TV06B330J-HF (Comchip)

Group 2 (1000W, 18.8A nominal): SMB10J33A-E3/52 (Vishay), SMB10J33A-E3/5B (Vishay)

Parameter Comparison

Part Number	Manufacturer	Voltage – Reverse Standoff (V)	Voltage – Breakdown Min (V)	Voltage – Clamping Max @ Ipp (V)	Current – Peak Pulse (A)	Power – Peak Pulse (W)	Package	Status
SMBJ33	Littelfuse Inc.	33	34.79	55.97	11.3	600	DO-214AA, SMB	Obsolete
SMBJ33A	Good-Ark Semiconductor	33	36.7	53.3	11.3	600	DO-214AA, SMB	Active
SZ1SMB33AT3G	Littelfuse	33	36.7	53.3	11.3	600	DO-214AA, SMB	Active
SMB10J33A-E3/52	Vishay General Semiconductor	33	36.7	53.3	18.8	1000	DO-214AA, SMB	Active
SMB10J33A-E3/5B	Vishay General Semiconductor	33	36.7	53.3	18.8	1000	DO-214AA, SMB	Active
SMBJ33A-13-F	Diodes Incorporated	33	36.7	53.3	11.3	600	DO-214AA, SMB	Active
SMBJ33A-TP	Micro Commercial Co	33	36.7	53.3	11.3	600	DO-214AA, SMB	Active
TV06B330J-G	Comchip Technology	33	36.7	53.3	11.26	600	DO-214AA, SMB	Active
TV06B330J-HF	Comchip Technology	33	36.7	53.3	11.26	600	DO-214AA, SMB	Active

Engineering Selection Recommendations

All substitute parts listed are ROHS3 compliant with MSL 1 (Unlimited) rating, matching the original SMBJ33 compliance profile. Selection between substitute options depends on application requirements and supply chain availability:

For direct electrical equivalence (600W, 11.3A): SMBJ33A (Good-Ark), SZ1SMB33AT3G (Littelfuse), SMBJ33A-13-F (Diodes Inc.), SMBJ33A-TP (Micro Commercial Co), TV06B330J-G (Comchip), or TV06B330J-HF (Comchip) provide identical electrical performance within the specified parameter ranges. SZ1SMB33AT3G carries AEC-Q101 automotive qualification and extended operating temperature range (−65 to 150°C), suitable for automotive and high-reliability applications.

For enhanced transient protection (1000W, 18.8A): SMB10J33A-E3/52 or SMB10J33A-E3/5B (Vishay TransZorb® series) offer higher peak pulse current and power dissipation capacity while maintaining the same 33V standoff voltage and DO-214AA SMB package. These parts provide additional margin for surge events but require circuit validation to confirm compatibility with existing design parameters.

Frequently Asked Questions (FAQ)

Q: Can I use SMB10J33A-E3/5B as a direct replacement for SMBJ33?

A: Yes, from a mechanical and electrical standpoint. Both parts share the same 33V reverse standoff voltage, DO-214AA SMB package, and surface-mount footprint. The SMB10J33A-E3/5B provides higher peak pulse current (18.8A vs. 11.3A) and power dissipation (1000W vs. 600W), making it suitable for applications requiring additional transient protection margin. Circuit validation is recommended to confirm compatibility with existing design parameters.

Q: What is the difference between SMBJ33A and SZ1SMB33AT3G?

A: Both parts maintain identical electrical specifications (33V standoff, 53.3V clamping, 11.3A peak pulse, 600W power). SZ1SMB33AT3G is manufactured by Littelfuse (the original SMBJ33 manufacturer) and carries AEC-Q101 automotive qualification with extended operating temperature range (−65 to 150°C). SMBJ33A is manufactured by Good-Ark Semiconductor with operating temperature range −55 to 150°C. Selection depends on automotive qualification requirements and temperature operating envelope.

Q: Are all substitute parts available in the same packaging options?

A: All substitute parts are supplied in Tape & Reel (TR) packaging for surface-mount assembly. SMBJ33A (Good-Ark) is also available in Cut Tape (CT) and Digi-Reel® formats. Confirm packaging availability with your supplier based on production volume and assembly requirements.

Q: What is the significance of the clamping voltage difference between SMBJ33 (55.97V) and substitute parts (53.3V)?

A: The SMBJ33 exhibits a higher maximum clamping voltage (55.97V) compared to most substitute parts (53.3V). Substitute parts with lower clamping voltage provide tighter voltage regulation during transient events, which may be beneficial for sensitive downstream circuitry. Circuit analysis is necessary to confirm that the lower clamping voltage does not introduce compatibility issues with existing protection thresholds.

Q: Do all substitute parts meet RoHS3 compliance?

A: Yes. All substitute parts listed are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, matching the original SMBJ33 environmental and regulatory profile.

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