P6SMBJ18C Equivalent & Substitute Parts

Part Overview

The P6SMBJ18C is a bidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component operates with a reverse standoff voltage of 15.3V and provides clamping at 26.78V with peak pulse current handling of 24.2A at 600W power dissipation. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for new designs and production continuity.

Key Parameters

Parameter	Value
Manufacturer Part Number	P6SMBJ18C
Manufacturer	Littelfuse Inc.
Category	Transient Voltage Suppressors (TVS)
Type	Zener
Bidirectional Channels	1
Voltage - Reverse Standoff (Typ)	15.3V
Voltage - Breakdown (Min)	16.2V
Voltage - Clamping (Max) @ Ipp	26.78V
Current - Peak Pulse (10/1000µs)	24.2A
Power - Peak Pulse	600W
Operating Temperature Range	-55°C ~ 150°C (TJ)
Mounting Type	Surface Mount
Package / Case	DO-214AA, SMB
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution of the P6SMBJ18C is determined by strict equivalence across the following critical parameters:

Electrical Compatibility Requirements:

Reverse standoff voltage: 15.3V (typ)
Breakdown voltage minimum: 16.2V or higher
Clamping voltage maximum: within acceptable range for circuit protection (26.78V reference)
Peak pulse current: 24.2A minimum
Power dissipation: 600W
Bidirectional operation: single channel

Mechanical & Environmental Requirements:

Package type: DO-214AA / SMB (surface mount)
Operating temperature range: minimum -55°C to 150°C
Moisture sensitivity: MSL 1 or equivalent
RoHS compliance: ROHS3 or equivalent

Regulatory & Availability Requirements:

Product status: Active preferred (obsolete acceptable for legacy support)
Compliance certifications: RoHS3, REACH unaffected

All substitute parts listed maintain these core parameters within acceptable engineering tolerances for direct replacement in the P6SMBJ18C application circuit.

Parameter Comparison

Parameter	P6SMBJ18C (Main)	SMBJP6KE18CA-TP	P6SMB18CA	P6SMB18CA-E3/52	P6SMB18CA-E3/5B	P6SMB18CAHE3_A/H	SM6T18CA	SM6T18CAY
Manufacturer	Littelfuse Inc.	Micro Commercial Co	Eaton - Electronics Division	Vishay General Semiconductor	Vishay General Semiconductor	Vishay General Semiconductor	STMicroelectronics	STMicroelectronics
Product Status	Obsolete	Active	Active	Active	Active	Obsolete	Active	Active
Voltage - Reverse Standoff (Typ)	15.3V	15.3V	15.3V	15.3V	15.3V	15.3V	15.3V	15.3V
Voltage - Breakdown (Min)	16.2V	17.1V	17.1V	17.1V	17.1V	17.1V	17.1V	17.1V
Voltage - Clamping (Max) @ Ipp	26.78V	25.5V	25.2V	25.2V	25.2V	25.2V	32.5V	32.5V
Current - Peak Pulse (10/1000µs)	24.2A	24.2A	24.2A	23.8A	23.8A	23.8A	123A (8/20µs)	123A (8/20µs)
Power - Peak Pulse	600W	600W	600W	600W	600W	600W	600W	600W
Operating Temperature Range	-55°C ~ 150°C	-55°C ~ 175°C	-55°C ~ 150°C	-65°C ~ 150°C	-65°C ~ 150°C	-65°C ~ 150°C	-55°C ~ 150°C	-55°C ~ 150°C
Package / Case	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB	DO-214AA, SMB
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	RoHS Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
Inventory Status	1008 Pcs	2671 Pcs	58000 Pcs	2050 Pcs	912 Pcs	6009 Pcs	3660 Pcs	10356 Pcs

Engineering Selection Recommendations

Primary Substitutes (Active Status, Recommended for New Designs):

P6SMB18CA (Eaton - Electronics Division) is the preferred primary substitute. This part maintains identical reverse standoff voltage (15.3V), equivalent clamping voltage (25.2V), and matching peak pulse current (24.2A) with active product status and highest inventory availability (58000 units). Operating temperature range of -55°C to 150°C matches the original specification. RoHS compliance and MSL 1 rating ensure compatibility with modern manufacturing processes.

SMBJP6KE18CA-TP (Micro Commercial Co) serves as a secondary active substitute with marginally lower clamping voltage (25.5V) and extended operating temperature range to 175°C. This part is suitable for applications requiring enhanced thermal performance.

Tertiary Substitutes (Active Status, Specialized Applications):

P6SMB18CA-E3/52 and P6SMB18CA-E3/5B (Vishay General Semiconductor) both provide extended operating temperature range (-65°C to 150°C) with clamping voltage of 25.2V and peak pulse current of 23.8A. These variants are appropriate for temperature-critical applications.

SM6T18CA and SM6T18CAY (STMicroelectronics) present higher clamping voltage (32.5V) and significantly elevated peak pulse current (123A at 8/20µs pulse). SM6T18CAY includes automotive-grade qualification (AEC-Q101). These parts are suitable only for applications where higher clamping voltage and current capacity are acceptable design parameters.

Legacy Substitutes (Obsolete Status):

P6SMB18CAHE3_A/H (Vishay General Semiconductor) carries obsolete status with automotive qualification (AEC-Q101). This part is reserved for legacy production support only.

Frequently Asked Questions (FAQ)

Q: Can P6SMB18CA directly replace P6SMBJ18C without circuit modification?

A: Yes. P6SMB18CA maintains the critical electrical parameters: 15.3V reverse standoff voltage, 25.2V clamping voltage, 24.2A peak pulse current, and 600W power dissipation. Both use DO-214AA/SMB packaging. No circuit redesign is required.

Q: What is the difference between clamping voltage specifications (26.78V vs 25.2V)?

A: The P6SMBJ18C specifies maximum clamping at 26.78V, while most active substitutes clamp at 25.2V. Both values fall within acceptable protection ranges for 15.3V standoff applications. The lower clamping voltage of substitutes provides marginally tighter voltage regulation. Circuit validation should confirm acceptability for specific overvoltage protection requirements.

Q: Why do SM6T18CA and SM6T18CAY show higher peak pulse current (123A)?

A: These STMicroelectronics parts use different pulse measurement standards (8/20µs vs 10/1000µs). The 123A specification reflects current capacity under 8/20µs pulse conditions, which is a more stringent industrial standard. These parts are not direct electrical equivalents and should be selected only when higher current capacity is a design requirement.

Q: Is P6SMB18CAHE3_A/H suitable for new production?

A: No. This part carries obsolete product status. It is reserved for legacy production support and end-of-life applications only. Select active alternatives for new designs.

Q: What packaging options are available?

A: All substitute parts use DO-214AA/SMB surface-mount packaging, identical to the original P6SMBJ18C. Packaging variants include Cut Tape (CT), Digi-Reel®, and Tape & Reel (TR) options depending on manufacturer and distributor. Verify packaging format with supplier for procurement requirements.

Q: Are all substitutes RoHS compliant?

A: Yes. All listed substitutes meet ROHS3 compliance or equivalent RoHS standards. Moisture sensitivity level is MSL 1 (unlimited) across all parts, ensuring compatibility with standard PCB assembly processes.

Q: Which substitute offers the best inventory availability?

A: P6SMB18CA (Eaton) provides the highest inventory level at 58,000 units, followed by SM6T18CAY (STMicroelectronics) at 10,356 units. For immediate procurement, these options offer the shortest lead times.

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