SMBJ18C Equivalent & Substitute Parts

Part Overview

The SMBJ18C is a bidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. The device features an 18V reverse standoff voltage with a 30.66V maximum clamping voltage at peak pulse current of 20.6A, housed in a DO-214AA (SMB) package with 600W peak pulse power rating. The original part is classified as obsolete, necessitating identification of functionally equivalent active alternatives from current manufacturers to maintain design continuity and ensure supply availability.

Key Parameters

Parameter	Value	Unit
Manufacturer Part Number	SMBJ18C	—
Manufacturer	Littelfuse Inc.	—
Category	Transient Voltage Suppressors (TVS)	—
Type	Zener, Bidirectional	—
Voltage - Reverse Standoff (Typ)	18	V
Voltage - Breakdown (Min)	18.95	V
Voltage - Clamping (Max) @ Ipp	30.66	V
Current - Peak Pulse (10/1000µs)	20.6	A
Power - Peak Pulse	600	W
Package / Case	DO-214AA, SMB	—
Operating Temperature Range	-65 to 150	°C (TJ)
Product Status	Obsolete	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the SMBJ18C is determined by strict electrical and mechanical compatibility across the following parameters:

Critical Matching Parameters:

Voltage - Reverse Standoff (Typ): 18V
Package / Case: DO-214AA, SMB (surface mount)
Bidirectional Channels: 1
Mounting Type: Surface Mount
RoHS Compliance: ROHS3 Compliant

Allowable Variation Parameters:

Voltage - Clamping (Max) @ Ipp: 29.2V to 32.2V (within acceptable clamp voltage range for 18V standoff class)
Current - Peak Pulse (10/1000µs): 18.6A to 34.25A (higher ratings provide enhanced protection margin)
Power - Peak Pulse: 600W to 1000W (higher ratings maintain or exceed original specification)
Operating Temperature Range: -50°C to 175°C (encompasses or exceeds original -65°C to 150°C range)

Substitute parts are grouped into two categories: direct electrical equivalents (matching clamping voltage and current specifications) and upgraded alternatives (higher power or current ratings with identical voltage characteristics).

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff (V)	Voltage - Clamping (Max) @ Ipp (V)	Current - Peak Pulse (A)	Power - Peak Pulse (W)	Operating Temp (°C)	Product Status
SMBJ18C	Littelfuse Inc.	18	30.66	20.6	600	-65 to 150	Obsolete
SMBJ18CA	MDD	18	29.2	20.6	600	-50 to 150	Active
SMBJ18C	Taiwan Semiconductor Corporation	18	32.2	19.5	600	-55 to 150	Active
TV06B180JB-G	Comchip Technology	18	29.2	20.55	600	Not specified	Active
TV06B180JB-HF	Comchip Technology	18	29.2	20.55	600	Not specified	Active
SMBJ18CAE3/TR13	Microchip Technology	18	29.2	20.5	600	-65 to 150	Active
SMBJ18CE3/TR13	Microchip Technology	18	32.2	18.6	600	-65 to 150	Active
1SMB18CA TR13 PBFREE	Central Semiconductor Corp	18	29.2	20.5	600	-65 to 150	Active
ATV06B180JB-HF	Comchip Technology	18	29.2	20.55	600	-55 to 150	Active
SMB10J18CA	Formosa Microsemi Co., Ltd.	18	29.2	34.2	1000	-55 to 175	Active
SMB10J18CA-TP	Micro Commercial Co	18	29.2	34.25	1000	-55 to 150	Active

Engineering Selection Recommendations

Direct Electrical Equivalents (Recommended Primary Substitutes):

Parts meeting or closely matching the original SMBJ18C electrical specifications with active product status:

SMBJ18CA (MDD): Matches 18V standoff, 20.6A peak pulse, and 600W power rating with 29.2V clamping voltage. Active status with ROHS3 compliance and unlimited moisture sensitivity level.
SMBJ18CAE3/TR13 (Microchip Technology): Matches 18V standoff, 20.5A peak pulse, and 600W power rating with 29.2V clamping voltage. Extended operating temperature range (-65°C to 150°C) aligns with original specification. Active status with ROHS3 compliance.
1SMB18CA TR13 PBFREE (Central Semiconductor Corp): Matches 18V standoff, 20.5A peak pulse, and 600W power rating with 29.2V clamping voltage. Extended operating temperature range (-65°C to 150°C). Active status with ROHS3 compliance.
TV06B180JB-HF (Comchip Technology): Matches 18V standoff, 20.55A peak pulse, and 600W power rating with 29.2V clamping voltage. Active status with ROHS3 compliance and unlimited moisture sensitivity level.

Higher Clamping Voltage Alternative:

SMBJ18CE3/TR13 (Microchip Technology): Provides 32.2V clamping voltage (closer to original 30.66V) with 18.6A peak pulse and 600W power rating. Extended operating temperature range (-65°C to 150°C). Active status with ROHS3 compliance. Suitable when lower clamping voltage margin is undesirable.

Upgraded Power Rating Alternatives (Enhanced Protection):

SMB10J18CA (Formosa Microsemi Co., Ltd.): Provides 1000W peak pulse power (versus 600W original) with 34.2A peak pulse current and 29.2V clamping voltage. Extended operating temperature range (-55°C to 175°C). Active status with ROHS3 compliance. Recommended for applications requiring higher transient energy absorption.
SMB10J18CA-TP (Micro Commercial Co): Provides 1000W peak pulse power with 34.25A peak pulse current and 29.2V clamping voltage. Active status with REACH unaffected designation. Suitable for demanding protection requirements.

Automotive Grade Alternative:

ATV06B180JB-HF (Comchip Technology): Automotive-qualified variant (AEC-Q101) with 29.2V clamping voltage, 20.55A peak pulse, and 600W power rating. Operating temperature range -55°C to 150°C. Recommended for automotive or mission-critical applications requiring automotive-grade qualification.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with a different clamping voltage?

A: Yes, within the allowable range. The SMBJ18C has a 30.66V maximum clamping voltage. Substitutes with 29.2V clamping voltage provide slightly tighter clamping (lower voltage spike), while those with 32.2V clamping voltage provide slightly looser clamping (higher voltage spike). Both remain within acceptable operating margins for 18V standoff class TVS diodes. Selection depends on circuit tolerance requirements.

Q: What is the difference between 600W and 1000W power-rated parts?

A: The 1000W variants (SMB10J series) absorb twice the transient energy compared to 600W parts. They are suitable for applications with higher transient current pulses or repeated surge events. The 600W rating of the original SMBJ18C is maintained in most direct equivalents; upgrade to 1000W only if circuit analysis indicates higher energy absorption is required.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 Compliant designation, matching the original SMBJ18C compliance status. This ensures compatibility with RoHS-regulated applications and procurement requirements.

Q: Can I use the automotive-grade ATV06B180JB-HF in non-automotive applications?

A: Yes. The ATV06B180JB-HF meets AEC-Q101 automotive qualification but is electrically and mechanically compatible with non-automotive designs. It provides the same 18V standoff, 29.2V clamping voltage, and 20.55A peak pulse as non-automotive equivalents. Use in non-automotive applications is acceptable and may provide additional reliability margin due to automotive-grade screening.

Q: What is the moisture sensitivity level (MSL) of substitute parts?

A: Most substitute parts specify MSL 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling. This matches the original SMBJ18C specification and simplifies supply chain management.

Q: Do substitute parts require different PCB footprints?

A: No. All substitute parts use the DO-214AA (SMB) surface-mount package, which maintains identical PCB footprint and land pattern compatibility with the original SMBJ18C. No PCB redesign is required for substitution.

Q: Which substitute offers the closest electrical match to the original SMBJ18C?

A: The SMBJ18CE3/TR13 (Microchip Technology) provides the closest clamping voltage match at 32.2V (versus original 30.66V) while maintaining 18V standoff, 600W power rating, and extended operating temperature range (-65°C to 150°C). This part is recommended when minimal electrical deviation from the original specification is required.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message