1KSMB27 Equivalent & Substitute Parts

Part Overview

The 1KSMB27 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., rated for 23.1V reverse standoff voltage with 39.38V clamping capability at 26.7A peak pulse current. This component is designed for general-purpose transient voltage protection in surface-mount applications using the DO-214AA (SMB) package. The part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

1KSMB27

Littelfuse Inc.In Stock: 9841KSMB27 Datasheet

Current PartRFQ

1KSMB27A

Taiwan Semiconductor CorporationIn Stock: 12281KSMB27A Datasheet

DirectRFQ

SZP6SMB27AT3G

onsemiIn Stock: 2160SZP6SMB27AT3G Datasheet

MFR RecommendedRFQ

SM6T27A-E3/5B

Vishay General Semiconductor - Diodes DivisionIn Stock: 923SM6T27A-E3/5B Datasheet

MFR RecommendedRFQ

SMBJP6KE27A-TP

Micro Commercial CoIn Stock: 1190SMBJP6KE27A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 1KSMB27 is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): 23.1V
• Package / Case: DO-214AA, SMB (surface-mount compatibility)
• Unidirectional Channels: 1
• Type: Zener
• Voltage - Clamping (Max) @ Ipp: 37.5V to 39.38V range
• Current - Peak Pulse (10/1000µs): 16A to 26.7A range
• Power - Peak Pulse: 600W to 1000W range
• Operating Temperature: -55°C minimum to 150°C maximum

All substitute parts listed maintain the same reverse standoff voltage (23.1V) and DO-214AA package footprint, ensuring mechanical and electrical compatibility. Variations in clamping voltage, peak pulse current, and power dissipation reflect different manufacturer specifications for the same voltage class, all within acceptable operating parameters for general-purpose TVS applications.

Parameter Comparison

Engineering Selection Recommendations

1KSMB27A (Taiwan Semiconductor Corporation) provides the closest electrical match to the original 1KSMB27, maintaining identical reverse standoff voltage (23.1V), peak pulse current (26.7A), and power dissipation (1000W). This part is active in production with ROHS3 compliance and extended operating temperature range (-55°C to 175°C). Packaging is supplied in Tape & Reel format.

SMBJP6KE27A-TP (Micro Commercial Co) offers active product status with ROHS3 compliance and extended temperature range (-55°C to 175°C). Peak pulse current is 16.3A with 600W power dissipation, representing a conservative design suitable for applications with lower transient energy requirements. Supplied in Tape & Reel packaging.

SM6T27A-E3/5B (Vishay General Semiconductor) is an active part with ROHS3 compliance, extended temperature range (-65°C to 150°C), and automotive-grade qualification (AEC-Q101). Peak pulse current is 16A with 600W power dissipation. This option is suitable for automotive and industrial applications requiring higher reliability standards. Supplied in Tape & Reel packaging.

SZP6SMB27AT3G (onsemi) is an active part with automotive-grade qualification (AEC-Q101) and extended temperature range (-65°C to 150°C). Peak pulse current is 16A with 600W power dissipation. This option provides automotive-level reliability for applications requiring AEC-Q101 certification. Supplied in bulk packaging.

All substitute parts maintain the same 23.1V reverse standoff voltage and DO-214AA package footprint, ensuring direct mechanical compatibility. Selection should be based on application power dissipation requirements, temperature operating range, and any automotive or industrial qualification requirements.

Frequently Asked Questions (FAQ)

Q: Can 1KSMB27A directly replace the obsolete 1KSMB27?

A: Yes. Both parts share identical reverse standoff voltage (23.1V), peak pulse current (26.7A), power dissipation (1000W), and DO-214AA package footprint. The 1KSMB27A is the recommended direct replacement, offering active product status and extended operating temperature range.

Q: What is the difference between the 1KSMB27 and the lower-current alternatives?

A: The original 1KSMB27 and 1KSMB27A are rated for 26.7A peak pulse current and 1000W power dissipation. The SZP6SMB27AT3G, SM6T27A-E3/5B, and SMBJP6KE27A-TP are rated for 16A to 16.3A peak pulse current and 600W power dissipation. Selection depends on the transient energy levels in your application. Higher-current designs require the 26.7A-rated parts.

Q: Are all substitute parts in the same DO-214AA package?

A: Yes. All listed substitute parts use the DO-214AA (SMB) surface-mount package, ensuring identical PCB footprint and mounting compatibility with the original 1KSMB27.

Q: Which substitute part should I use for automotive applications?

A: Both SZP6SMB27AT3G (onsemi) and SM6T27A-E3/5B (Vishay) carry AEC-Q101 automotive qualification. If your application requires automotive-grade components, select from these two options based on your power dissipation requirements.

Q: What is the impact of clamping voltage differences between parts?

A: The original 1KSMB27 clamps at 39.38V maximum, while substitute parts clamp at 37.5V maximum. Both values are within the same voltage class (23.1V standoff). The lower clamping voltage in substitutes provides slightly tighter transient suppression. Verify your circuit design can tolerate the 37.5V clamping level before selection.

Q: Can I use SZP6SMB27AT3G in place of higher-current rated parts?

A: SZP6SMB27AT3G is rated for 16A peak pulse current and 600W power dissipation, compared to 26.7A and 1000W for the original 1KSMB27. Use this part only if your application transient energy is within the 600W limit. For higher-energy transients, select 1KSMB27A or SMBJP6KE27A-TP.

Q: What packaging formats are available?

A: 1KSMB27A, SM6T27A-E3/5B, and SMBJP6KE27A-TP are supplied in Tape & Reel format. SZP6SMB27AT3G is supplied in bulk packaging. Verify packaging compatibility with your procurement and assembly processes.