1KSMB15 Equivalent & Substitute Parts

Part Overview

The 1KSMB15 is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 12.8V reverse standoff voltage, 22.26V maximum clamping voltage, and 47.2A peak pulse current capability in a DO-214AA (SMB) package. The part is currently listed as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and procurement.

Substiute Parts

1KSMB15

Littelfuse Inc.In Stock: 9241KSMB15 Datasheet

Current PartRFQ

1KSMB15A

Taiwan Semiconductor CorporationIn Stock: 93641KSMB15A Datasheet

DirectRFQ

SM6T15A-E3/5B

Vishay General Semiconductor - Diodes DivisionIn Stock: 3852SM6T15A-E3/5B Datasheet

MFR RecommendedRFQ

SMBJP6KE15A-TP

Micro Commercial CoIn Stock: 1493SMBJP6KE15A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 1KSMB15 is determined by the following critical parameters:

• Voltage Rating Match: Reverse standoff voltage of 12.8V and breakdown voltage minimum of 14.65V
• Clamping Voltage Compatibility: Maximum clamping voltage at peak pulse current must not exceed 22.26V to maintain circuit protection integrity
• Peak Pulse Current: Minimum 47.2A capability at 10/1000µs pulse profile
• Package Compatibility: DO-214AA (SMB) surface-mount package required for PCB layout compatibility
• Compliance Requirements: ROHS3 compliance and MSL 1 rating mandatory

The identified substitute parts meet these core electrical and mechanical criteria while offering active product status and improved availability compared to the obsolete 1KSMB15.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: 1KSMB15A (Taiwan Semiconductor Corporation)

The 1KSMB15A provides the closest electrical match to the 1KSMB15, maintaining identical reverse standoff voltage (12.8V), peak pulse current (47.2A), and power dissipation (1000W). This part is actively manufactured, ROHS3 compliant, and available in high inventory (9300 pcs). The extended operating temperature range (-55°C to 175°C) provides additional thermal margin. Packaging is supplied as Tape & Reel (TR), standard for production environments.

Secondary Substitutes: SM6T15A-E3/5B (Vishay) and SMBJP6KE15A-TP (Micro Commercial)

Both alternatives maintain the critical 12.8V reverse standoff voltage and 21.2V clamping voltage specification. However, peak pulse current is reduced to 28A and 28.8A respectively, with corresponding power dissipation of 600W. These parts are suitable for applications where the original 47.2A peak pulse current specification exceeds circuit requirements. Both are actively produced, ROHS3 compliant, and available in production quantities. The Vishay part offers extended lower temperature rating (-65°C minimum), while the Micro Commercial part supports -55°C to 175°C operation.

Frequently Asked Questions (FAQ)

Q: Can the 1KSMB15A directly replace the 1KSMB15 without circuit modification?

A: Yes. The 1KSMB15A maintains identical voltage ratings (12.8V standoff, 14.65V minimum breakdown) and peak pulse current (47.2A), ensuring equivalent protection performance. The DO-214AA package is mechanically identical, requiring no PCB layout changes.

Q: What is the key difference between the 1KSMB15A and the Vishay SM6T15A-E3/5B?

A: The primary difference is peak pulse current capability. The 1KSMB15A handles 47.2A at 1000W, while the SM6T15A-E3/5B is rated for 28A at 600W. Both maintain the same 12.8V standoff and 21.2V clamping voltages. Selection depends on whether the circuit requires the higher current handling of the 1KSMB15A or if 28A is sufficient for the application.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. The 1KSMB15A, SM6T15A-E3/5B, and SMBJP6KE15A-TP are all ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, matching the original 1KSMB15 compliance profile.

Q: Does package type affect substitution compatibility?

A: No. All substitute parts use the DO-214AA (SMB) surface-mount package, identical to the original 1KSMB15. Tape & Reel (TR) packaging is a supply format difference only and does not affect electrical or mechanical compatibility on the PCB.

Q: Which substitute offers the widest operating temperature range?

A: The 1KSMB15A and SMBJP6KE15A-TP both support -55°C to 175°C operation, exceeding the original 1KSMB15 specification of -55°C to 150°C. The Vishay SM6T15A-E3/5B extends the lower limit to -65°C but maintains the 150°C upper limit.