1KSMB18 Equivalent & Substitute Parts

Part Overview

The 1KSMB18 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 15.3V reverse standoff voltage, 26.78V maximum clamping voltage, and 39.2A peak pulse current capability in a DO-214AA (SMB) package. The 1KSMB18 is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement continuity.

Substiute Parts

1KSMB18

Littelfuse Inc.In Stock: 11341KSMB18 Datasheet

Current PartRFQ

1KSMB18A

Taiwan Semiconductor CorporationIn Stock: 20041KSMB18A Datasheet

DirectRFQ

P6SMB18A-E3/5B

Vishay General Semiconductor - Diodes DivisionIn Stock: 1108P6SMB18A-E3/5B Datasheet

MFR RecommendedRFQ

SMBJP6KE18A-TP

Micro Commercial CoIn Stock: 3038SMBJP6KE18A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1KSMB18 is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): 15.3V
• Voltage - Clamping (Max) @ Ipp: 25.2V to 26.78V range
• Current - Peak Pulse (10/1000µs): 23.8A minimum
• Package / Case: DO-214AA, SMB
• Mounting Type: Surface Mount
• Type: Zener, Unidirectional

The substitute parts listed below maintain compatibility within these electrical and mechanical specifications while offering active product status and improved availability.

Parameter Comparison

Engineering Selection Recommendations

1KSMB18A (Taiwan Semiconductor Corporation) provides the closest electrical match to the original 1KSMB18, maintaining identical reverse standoff voltage (15.3V), peak pulse current (39.2A), and peak pulse power (1000W). This part is active and available in Tape & Reel packaging with extended operating temperature range (-55°C ~ 175°C). ROHS3 compliance and unlimited MSL rating ensure compatibility with current manufacturing standards.

P6SMB18A-E3/5B (Vishay General Semiconductor) offers active product status with identical reverse standoff voltage and clamping voltage within acceptable tolerance (25.2V vs. 26.78V). Peak pulse current is reduced to 23.8A with 600W power rating. This part is suitable for applications where lower current handling is acceptable. Extended temperature range (-65°C ~ 150°C) and ROHS3 compliance are provided.

SMBJP6KE18A-TP (Micro Commercial Co) maintains identical reverse standoff voltage (15.3V) and clamping voltage (25.5V) with 24.2A peak pulse current and 600W power rating. Active product status, extended operating temperature (-55°C ~ 175°C), and ROHS3 compliance support modern design requirements. Highest inventory availability (3007 pcs) among substitute options.

Frequently Asked Questions (FAQ)

Q: Can the 1KSMB18A directly replace the obsolete 1KSMB18?

A: Yes. The 1KSMB18A maintains identical electrical specifications for reverse standoff voltage (15.3V), peak pulse current (39.2A), and peak pulse power (1000W). Both use DO-214AA SMB packaging. The substitute offers extended operating temperature range and active product status.

Q: What is the difference between the 1KSMB18A and P6SMB18A-E3/5B?

A: The 1KSMB18A provides higher peak pulse current (39.2A vs. 23.8A) and power dissipation (1000W vs. 600W). The P6SMB18A-E3/5B offers extended lower temperature rating (-65°C vs. -55°C). Both maintain the same reverse standoff voltage (15.3V) and use identical DO-214AA SMB packaging. Selection depends on application current requirements.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (1KSMB18A, P6SMB18A-E3/5B, SMBJP6KE18A-TP) are ROHS3 compliant with unlimited MSL rating (1), ensuring compatibility with current manufacturing and environmental standards.

Q: What is the package compatibility for these TVS diodes?

A: All parts use DO-214AA SMB surface-mount package. Physical footprint and land pattern are identical across all listed parts, allowing direct PCB substitution without layout modifications.

Q: Which substitute offers the best availability?

A: SMBJP6KE18A-TP from Micro Commercial Co currently has the highest inventory (3007 pcs), followed by 1KSMB18A (1900 pcs) and P6SMB18A-E3/5B (1024 pcs).