SMDJ33 Equivalent & Substitute Parts

Part Overview

The SMDJ33 is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. Specified with a 33V reverse standoff voltage and 55.97V maximum clamping voltage at 56.3A peak pulse current, the SMDJ33 operates across -65°C to 150°C and is packaged in DO-214AB (SMC). The part is currently listed as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for new designs and production continuity.

Key Parameters

Parameter	Value
Voltage - Reverse Standoff (Typ)	33V
Voltage - Breakdown (Min)	34.79V
Voltage - Clamping (Max) @ Ipp	55.97V
Current - Peak Pulse (10/1000µs)	56.3A
Power - Peak Pulse	3000W (3kW)
Operating Temperature Range	-65°C ~ 150°C (TJ)
Package / Case	DO-214AB, SMC
Type	Zener, Unidirectional
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution of the SMDJ33 is determined by strict electrical and mechanical parameter alignment:

Primary Substitution Criteria:

Reverse standoff voltage: 33V (matching specification)
Clamping voltage range: 53.3V to 55.97V (acceptable variation within design margin)
Peak pulse current: 28.1A to 56.3A (application-dependent selection)
Power dissipation: 1500W to 3000W (application-dependent selection)
Package: DO-214AB / SMC (mechanical compatibility)
Operating temperature: minimum -55°C to -65°C; maximum 150°C or higher

Substitute parts are grouped into two categories based on peak pulse current and power rating:

Group A (Full Performance Match): 56.2A to 56.3A peak pulse current, 3000W power rating

SMDJ33A (Alpha & Omega Semiconductor)
SMLJ33A (Bourns Inc.)
SMLJ33A-TP (Micro Commercial Co)
SMLJ33AE3/TR13 (Microchip Technology)
TV30C330J-G (Comchip Technology)

Group B (Reduced Performance): 28.1A to 28.2A peak pulse current, 1500W power rating

SMCJ33A (MDD)
SMCJ33AE3/TR13 (Microchip Technology)
TV15C330J-G (Comchip Technology)

Selection between groups depends on circuit peak pulse current requirements. Group A maintains full electrical performance parity with the original SMDJ33. Group B provides functional overvoltage protection at reduced current capacity.

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff	Voltage - Clamping (Max) @ Ipp	Current - Peak Pulse (10/1000µs)	Power - Peak Pulse	Operating Temperature	Package	Product Status
SMDJ33	Littelfuse Inc.	33V	55.97V	56.3A	3000W	-65°C ~ 150°C	DO-214AB, SMC	Obsolete
SMDJ33A	Alpha & Omega Semiconductor	33V	53.3V	56.3A	3000W	-55°C ~ 150°C	DO-214AB, SMC	Active
SMCJ33A	MDD	33V	53.3V	28.2A	1500W	-50°C ~ 150°C	DO-214AB, SMC	Active
SMCJ33AE3/TR13	Microchip Technology	33V	53.3V	28.1A	1500W	-65°C ~ 150°C	DO-214AB, SMC	Active
SMLJ33A	Bourns Inc.	33V	53.3V	56.2A	3000W	-55°C ~ 150°C	DO-214AB, SMC	Active
SMLJ33A-TP	Micro Commercial Co	33V	53.3V	56.2A	3000W	-55°C ~ 175°C	DO-214AB, SMC	Active
SMLJ33AE3/TR13	Microchip Technology	33V	53.3V	56.2A	300W	-55°C ~ 150°C	DO-214AB, SMC	Active
TV15C330J-G	Comchip Technology	33V	53.3V	28.14A	1500W	-55°C ~ 150°C	DO-214AB, SMC	Active
TV30C330J-G	Comchip Technology	33V	53.3V	56.29A	3000W	-55°C ~ 150°C	DO-214AB, SMC	Active

Engineering Selection Recommendations

For applications requiring full electrical performance parity (56+ A peak pulse, 3000W):

SMLJ33A-TP (Micro Commercial Co) is the primary recommendation. It provides 56.2A peak pulse current, 3000W power dissipation, extended operating temperature to 175°C, and active product status with ROHS3 compliance and unlimited moisture sensitivity level. Tape & Reel packaging supports high-volume production.

SMDJ33A (Alpha & Omega Semiconductor) offers equivalent 56.3A peak pulse and 3000W rating with active status and ROHS3 compliance. Operating temperature minimum of -55°C is acceptable for most applications. High inventory availability (230,383 pcs) supports supply continuity.

TV30C330J-G (Comchip Technology) provides 56.29A peak pulse and 3000W power with active status and ROHS3 compliance. Suitable where Comchip Technology qualification is required.

For applications with reduced peak pulse current requirements (28 A, 1500W):

SMCJ33AE3/TR13 (Microchip Technology) is recommended for extended temperature range applications. It maintains the original SMDJ33 operating temperature floor of -65°C, provides 28.1A peak pulse current, 1500W power dissipation, and active product status with ROHS3 compliance.

TV15C330J-G (Comchip Technology) provides equivalent 28.14A peak pulse and 1500W power with active status and ROHS3 compliance.

All recommended substitutes maintain DO-214AB / SMC package compatibility, 33V reverse standoff voltage specification, and ROHS3 compliance with the original SMDJ33.

Frequently Asked Questions (FAQ)

Q: Can SMDJ33A directly replace SMDJ33 in existing designs?

A: SMDJ33A maintains electrical compatibility with 33V reverse standoff voltage, 56.3A peak pulse current, and 3000W power rating. The clamping voltage is 53.3V versus 55.97V on the original, representing a 2.67V reduction within typical design margins. Operating temperature minimum is -55°C versus -65°C; verify your application's minimum temperature requirement. Package and pinout are identical (DO-214AB / SMC).

Q: What is the difference between Group A and Group B substitutes?

A: Group A substitutes (SMDJ33A, SMLJ33A, SMLJ33A-TP, SMLJ33AE3/TR13, TV30C330J-G) provide 56+ A peak pulse current and 3000W power dissipation, matching the original SMDJ33 performance. Group B substitutes (SMCJ33A, SMCJ33AE3/TR13, TV15C330J-G) provide 28 A peak pulse current and 1500W power dissipation. Select Group A for circuits designed for the full 56.3A specification. Select Group B only if your circuit peak pulse current is specified at 28 A or lower.

Q: Are all substitutes ROHS3 compliant?

A: All listed substitute parts are ROHS3 compliant. Verify REACH status with your supplier if REACH compliance is required for your application.

Q: Does packaging format affect electrical performance?

A: No. Tape & Reel (TR) and Cut Tape (CT) packaging formats do not affect electrical performance. They differ only in supply format for manufacturing. Select based on your production equipment and volume requirements.

Q: What is the significance of the clamping voltage difference (55.97V vs. 53.3V)?

A: The clamping voltage is the maximum voltage across the TVS diode when conducting peak pulse current. The 2.67V difference between SMDJ33 (55.97V) and most substitutes (53.3V) represents lower clamping performance. For circuits with tight voltage margin requirements, verify that 53.3V clamping is acceptable. For general-purpose overvoltage protection, this difference is typically within design tolerance.

Q: Can SMLJ33AE3/TR13 be used as a direct substitute?

A: SMLJ33AE3/TR13 provides 56.2A peak pulse current and matches the original operating temperature range (-55°C to 150°C). However, its power rating is specified as 300W, significantly lower than the original 3000W. This part is suitable only for applications where peak pulse power dissipation does not exceed 300W. Do not use as a direct substitute for the full 3000W specification.

Q: Which substitute has the widest operating temperature range?

A: SMLJ33A-TP (Micro Commercial Co) operates from -55°C to 175°C, providing the highest maximum temperature rating. SMCJ33AE3/TR13 (Microchip Technology) maintains the original -65°C minimum temperature floor. Select based on your application's specific temperature requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message