SMBJ48 Equivalent & Substitute Parts

Part Overview

The SMBJ48 is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. The device features a 48V reverse standoff voltage with an 81.27V maximum clamping voltage at peak pulse current, housed in a DO-214AA (SMB) package. The SMBJ48 is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across voltage ratings, peak pulse current specifications, and thermal operating ranges while conforming to the same package and mounting standards.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	48	V
Voltage - Breakdown (Min)	50.49	V
Voltage - Clamping (Max) @ Ipp	81.27	V
Current - Peak Pulse (10/1000µs)	7.8	A
Power - Peak Pulse	600	W
Operating Temperature Range	-65 to 150	°C (TJ)
Package / Case	DO-214AA, SMB	—
Mounting Type	Surface Mount	—
RoHS Status	ROHS3 Compliant	—
Moisture Sensitivity Level	1 (Unlimited)	—

Substitute Part Grouping Explanation

Substitute parts for the SMBJ48 are selected based on strict electrical and mechanical compatibility criteria. The primary substitution parameters are:

Voltage - Reverse Standoff: Must equal 48V (±0V tolerance for direct substitution)
Voltage - Clamping (Max) @ Ipp: Must fall within acceptable range (77.4V to 81.27V)
Current - Peak Pulse (10/1000µs): Must be ≥7.7A to maintain protection capability
Power - Peak Pulse: Must equal or exceed 600W
Package / Case: Must be DO-214AA or SMB (equivalent footprint)
Mounting Type: Must be Surface Mount
RoHS Status: Must be ROHS3 Compliant
Moisture Sensitivity Level: Must be 1 (Unlimited)

All identified substitute parts meet these criteria and are classified as Active products, ensuring long-term availability and supply chain reliability compared to the obsolete SMBJ48.

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff (V)	Voltage - Clamping (Max) @ Ipp (V)	Current - Peak Pulse (A)	Power - Peak Pulse (W)	Operating Temperature (°C)	Product Status	Package
SMBJ48	Littelfuse Inc.	48	81.27	7.8	600	-65 to 150	Obsolete	DO-214AA (SMB)
SMBJ48A	Meritek	48	77.4	7.75	600	-55 to 150	Active	DO-214AA (SMB)
SZ1SMB48AT3G	Littelfuse Inc.	48	77.4	7.7	600	-65 to 150	Active	DO-214AA (SMB)
SMBJ48A-13-F	Diodes Incorporated	48	77.4	7.7	600	-55 to 150	Active	DO-214AA (SMB)
SMBJ48A-E3/5B	Vishay General Semiconductor - Diodes Division	48	77.4	7.8	600	-55 to 150	Active	DO-214AA (SMB)
SMBJ48A-M3/52	Vishay General Semiconductor - Diodes Division	48	77.4	7.8	600	-55 to 150	Active	DO-214AA (SMB)
SMBJ48A-M3/5B	Vishay General Semiconductor - Diodes Division	48	77.4	7.8	600	-55 to 150	Active	DO-214AA (SMB)
SMBJ48A-TP	Micro Commercial Co	48	77.4	7.7	600	-55 to 175	Active	DO-214AA (SMB)
SMBJ48A-TR	STMicroelectronics	48	77.4	8.1	600	-55 to 150	Active	DO-214AA (SMB)

Engineering Selection Recommendations

All substitute parts listed are classified as Active products with ROHS3 compliance and MSL 1 (Unlimited) ratings, ensuring regulatory compliance and supply chain continuity. The SZ1SMB48AT3G from Littelfuse Inc. maintains the original manufacturer's design lineage and preserves the -65°C lower operating temperature limit of the obsolete SMBJ48, making it the preferred direct replacement for applications requiring extended low-temperature performance. The SMBJ48A-TP from Micro Commercial Co extends the upper operating temperature to 175°C, providing enhanced thermal margin for high-ambient applications. Vishay TransZorb® variants (SMBJ48A-E3/5B, SMBJ48A-M3/52, SMBJ48A-M3/5B) offer established automotive-grade reliability through AEC-Q101 qualification where applicable. All substitute parts maintain the 48V reverse standoff voltage and 600W peak pulse power rating, with clamping voltages ranging from 77.4V to 81.27V, ensuring functional equivalence within the specified protection envelope.

Frequently Asked Questions (FAQ)

Q: Can SMBJ48A substitute directly for the obsolete SMBJ48?

A: Yes. The SMBJ48A from Meritek maintains the 48V reverse standoff voltage, 600W peak pulse power, and DO-214AA (SMB) package compatibility. The clamping voltage is 77.4V compared to the original 81.27V, which remains within acceptable overvoltage protection parameters. The operating temperature range is -55°C to 150°C versus the original -65°C to 150°C.

Q: What is the difference between SMBJ48A variants from different manufacturers?

A: All SMBJ48A variants share the same electrical specifications (48V standoff, 77.4V clamping, 600W peak pulse) and DO-214AA package. Differences exist in packaging format (Tape & Reel vs. Cut Tape), operating temperature ranges, and manufacturer certifications. Vishay variants include AEC-Q101 automotive qualification; Micro Commercial Co's SMBJ48A-TP extends to 175°C; STMicroelectronics SMBJ48A-TR provides 8.1A peak pulse current.

Q: Is the SZ1SMB48AT3G a better choice than SMBJ48A for low-temperature applications?

A: The SZ1SMB48AT3G from Littelfuse Inc. maintains the -65°C lower temperature limit of the original SMBJ48, compared to -55°C for most SMBJ48A variants. For applications requiring operation below -55°C, SZ1SMB48AT3G is the appropriate selection. Both devices are Active products with equivalent electrical performance.

Q: Do all substitute parts have the same package footprint?

A: Yes. All substitute parts use the DO-214AA (SMB) surface-mount package, ensuring PCB footprint compatibility. Packaging formats vary (Tape & Reel, Cut Tape, Digi-Reel®), but the physical component dimensions and lead configuration remain identical.

Q: Are there any compliance or certification differences between substitutes?

A: All substitute parts are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity ratings. The SZ1SMB48AT3G includes AEC-Q101 automotive qualification. Vishay TransZorb® variants (SMBJ48A-E3/5B, SMBJ48A-M3/52, SMBJ48A-M3/5B) carry the TransZorb® brand designation and automotive-grade reliability. Standard industrial-grade variants from Meritek, Diodes Incorporated, Micro Commercial Co, and STMicroelectronics meet general-purpose protection requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message