SMAJ45A-TP Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SMAJ45A-TP is a unidirectional Zener-type transient voltage suppressor manufactured by Micro Commercial Co, designed for general-purpose overvoltage protection in surface-mount applications. This DO-214AC (SMA) package device operates across -55°C to 175°C and is ROHS3 compliant with unlimited moisture sensitivity rating. The part is currently active in production with 853 units in stock. Substitute parts are identified to address supply chain requirements, alternative sourcing needs, or specific application constraints while maintaining electrical and mechanical compatibility.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	45	V
Voltage - Breakdown (Min)	50	V
Voltage - Clamping (Max) @ Ipp	72.7	V
Current - Peak Pulse (10/1000µs)	5.5	A
Power - Peak Pulse	400	W
Operating Temperature Range	-55 to 175	°C
Package / Case	DO-214AC, SMA	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution eligibility for the SMAJ45A-TP is determined by strict alignment of the following critical parameters:

Mandatory Matching Parameters:

Voltage - Reverse Standoff (Typ): 45V
Voltage - Breakdown (Min): 50V
Current - Peak Pulse (10/1000µs): 5.5A
Power - Peak Pulse: 400W
Package / Case: DO-214AC, SMA
Mounting Type: Surface Mount
Type: Zener
Unidirectional Channels: 1

Acceptable Variation:

Voltage - Clamping (Max) @ Ipp: 72.7V (primary specification); minor variations acceptable within application tolerance
Operating Temperature Range: Minimum -55°C and maximum ≥150°C required

Classification:

Direct Substitutes: Parts matching all mandatory parameters with identical clamping voltage (72.7V) and peak pulse current (5.5A)
Similar Substitutes: Parts matching all mandatory parameters with acceptable variations in clamping voltage or peak pulse current within the same power class

Parameter Comparison

Manufacturer Part Number	Manufacturer	Voltage - Reverse Standoff (Typ)	Voltage - Breakdown (Min)	Voltage - Clamping (Max) @ Ipp	Current - Peak Pulse (10/1000µs)	Power - Peak Pulse	Operating Temperature Range	Package / Case	Product Status
SMAJ45A-TP	Micro Commercial Co	45V	50V	72.7V	5.5A	400W	-55°C ~ 175°C	DO-214AC, SMA	Active
SMAJ45A	Meritek	45V	50V	72.7V	5.5A	400W	-55°C ~ 150°C	DO-214AC (SMA)	Active
SMAJ45A-13-F	Diodes Incorporated	45V	50V	72.7V	5.5A	400W	-55°C ~ 150°C	DO-214AC, SMA	Active
SMAJ45A-E3/61	Vishay General Semiconductor - Diodes Division	45V	50V	72.7V	5.5A	400W	-55°C ~ 150°C	DO-214AC, SMA	Active
SMAJ45AHR3G	Taiwan Semiconductor Corporation	45V	50V	72.7V	5.5A	400W	-55°C ~ 150°C	DO-214AC, SMA	Active
SMAJ45HR3G	Taiwan Semiconductor Corporation	45V	50V	80.3V	5A	400W	-55°C ~ 150°C	DO-214AC, SMA	Active

Engineering Selection Recommendations

Direct Substitutes (Identical Electrical Performance):

SMAJ45A (Meritek), SMAJ45A-13-F (Diodes Incorporated), SMAJ45A-E3/61 (Vishay General Semiconductor - Diodes Division), and SMAJ45AHR3G (Taiwan Semiconductor Corporation) are direct functional equivalents. All maintain 45V reverse standoff, 50V minimum breakdown, 72.7V clamping voltage, and 5.5A peak pulse current specifications. All are ROHS3 compliant with unlimited moisture sensitivity rating and active production status. Operating temperature range is -55°C to 150°C, which is acceptable for applications not requiring the extended 175°C upper limit of the SMAJ45A-TP.

SMAJ45AHR3G carries AEC-Q101 automotive qualification and is graded for automotive applications, providing additional reliability assurance for automotive-grade circuit protection requirements.

Similar Substitute (Acceptable Variation):

SMAJ45HR3G (Taiwan Semiconductor Corporation) exhibits variations in clamping voltage (80.3V versus 72.7V) and peak pulse current (5A versus 5.5A) while maintaining the 400W power rating and identical package specifications. This part is suitable only for applications where the higher clamping voltage and reduced peak pulse current are within design tolerance. AEC-Q101 automotive qualification is provided.

All substitute parts are currently in active production with confirmed inventory availability.

Frequently Asked Questions (FAQ)

Q: Can SMAJ45A (Meritek) replace SMAJ45A-TP in all applications?

A: SMAJ45A is a direct electrical equivalent with identical voltage and current specifications. The primary difference is the operating temperature range: SMAJ45A operates to 150°C maximum versus 175°C for SMAJ45A-TP. Substitution is valid for applications where circuit operation does not exceed 150°C.

Q: What is the difference between SMAJ45AHR3G and SMAJ45HR3G?

A: Both are manufactured by Taiwan Semiconductor Corporation with AEC-Q101 automotive qualification. SMAJ45AHR3G maintains the 72.7V clamping voltage and 5.5A peak pulse current of the original SMAJ45A-TP. SMAJ45HR3G has a higher clamping voltage (80.3V) and lower peak pulse current (5A). Select SMAJ45AHR3G for direct replacement; select SMAJ45HR3G only if the higher clamping voltage and reduced current are acceptable for your circuit design.

Q: Are all substitute parts in the same DO-214AC (SMA) package?

A: Yes. All listed substitute parts use the DO-214AC (SMA) surface-mount package, ensuring mechanical and footprint compatibility with the SMAJ45A-TP.

Q: Do all substitute parts meet ROHS3 compliance?

A: Yes. All substitute parts listed are ROHS3 compliant with unlimited moisture sensitivity rating (MSL 1), matching the compliance profile of SMAJ45A-TP.

Q: Which substitute part is recommended for automotive applications?

A: SMAJ45AHR3G and SMAJ45HR3G both carry AEC-Q101 automotive qualification. SMAJ45AHR3G is the direct electrical equivalent; SMAJ45HR3G is suitable only if the higher clamping voltage and reduced peak pulse current align with application requirements.

Q: Can SMAJ45HR3G be used as a direct replacement?

A: SMAJ45HR3G is not a direct replacement due to differences in clamping voltage (80.3V versus 72.7V) and peak pulse current (5A versus 5.5A). Use only if circuit design tolerates these parameter variations and the higher clamping voltage does not exceed downstream component voltage ratings.

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