SMAJ150 Equivalent & Substitute Parts

Part Overview

The SMAJ150 is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. The device features a 150V reverse standoff voltage with a 255.15V maximum clamping voltage and 1.6A peak pulse current capability in a DO-214AC (SMA) package. The SMAJ150 is classified as obsolete, necessitating identification of active equivalent and substitute parts that maintain electrical and mechanical compatibility for new designs and production continuity.

Substiute Parts

SMAJ150

Littelfuse Inc.In Stock: 4581SMAJ150 Datasheet

Current PartRFQ

SMAJ150A

MDDIn Stock: 20427SMAJ150A Datasheet

DirectRFQ

SMAJ150A

MDDIn Stock: 20427SMAJ150A Datasheet

DirectRFQ

SMAJ150A-13-F

Diodes IncorporatedIn Stock: 18538SMAJ150A-13-F Datasheet

MFR RecommendedRFQ

SMAJ150A-TP

Micro Commercial CoIn Stock: 4482SMAJ150A-TP Datasheet

MFR RecommendedRFQ

SMAJ150AE3/TR13

Microchip TechnologyIn Stock: 840SMAJ150AE3/TR13 Datasheet

MFR RecommendedRFQ

SMAJ150E3/TR13

Microchip TechnologyIn Stock: 739SMAJ150E3/TR13 Datasheet

MFR RecommendedRFQ

SMAJ154A-TR

STMicroelectronicsIn Stock: 2618SMAJ154A-TR Datasheet

MFR RecommendedRFQ

TV04A151J-G

Comchip TechnologyIn Stock: 828TV04A151J-G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMAJ150 is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): 150V
• Voltage - Clamping (Max) @ Ipp: 243V to 268V range
• Current - Peak Pulse (10/1000µs): 1.6A to 2.1A range
• Package / Case: DO-214AC, SMA
• Type: Zener, Unidirectional
• RoHS Status: ROHS3 Compliant
• Mounting Type: Surface Mount

Substitute parts are grouped into two categories based on electrical performance:

Group 1 - Direct Electrical Equivalents (243V Clamping): SMAJ150A (MDD), SMAJ150A-13-F (Diodes Incorporated), SMAJ150A-TP (Micro Commercial Co), and TV04A151J-G (Comchip Technology). These parts maintain the 150V reverse standoff voltage with 243V clamping voltage and 1.6A to 1.65A peak pulse current, providing direct functional replacement.

Group 2 - Enhanced Performance Alternatives: SMAJ150AE3/TR13 (Microchip Technology) with 2.1A peak pulse current and 500W power rating, and SMAJ150E3/TR13 (Microchip Technology) with 268V clamping voltage and 1.9A peak pulse current. These parts exceed the original specifications while maintaining 150V reverse standoff voltage and DO-214AC packaging.

Non-Equivalent Part: SMAJ154A-TR (STMicroelectronics) features 154V reverse standoff voltage and is not a direct substitute due to different voltage rating.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: SMAJ150A (MDD), SMAJ150A-13-F (Diodes Incorporated), SMAJ150A-TP (Micro Commercial Co), and TV04A151J-G (Comchip Technology) are functionally equivalent to the obsolete SMAJ150. All are ROHS3 compliant with MSL 1 rating and active product status. SMAJ150A-TP offers the widest operating temperature range (-55°C to 175°C), providing additional thermal margin for high-temperature applications.

For Enhanced Performance Requirements: SMAJ150AE3/TR13 and SMAJ150E3/TR13 (both Microchip Technology) provide increased peak pulse current (2.1A and 1.9A respectively) and higher power dissipation (500W), while maintaining 150V reverse standoff voltage and DO-214AC packaging. These parts are suitable for applications requiring higher transient energy absorption.

Not Recommended: SMAJ154A-TR features a different reverse standoff voltage (154V) and is not electrically equivalent to the SMAJ150.

All recommended substitute parts maintain ROHS3 compliance, MSL 1 moisture sensitivity rating, and surface-mount DO-214AC (SMA) packaging compatibility with the original SMAJ150.

Frequently Asked Questions (FAQ)

Q: Can SMAJ150A directly replace SMAJ150 in existing designs?

A: Yes. SMAJ150A maintains the same 150V reverse standoff voltage, 1.6A peak pulse current, and DO-214AC (SMA) package. The 243V clamping voltage is within acceptable tolerance for general-purpose overvoltage protection applications. All substitute parts in Group 1 are direct functional replacements.

Q: What is the difference between the 243V and 268V clamping voltage options?

A: SMAJ150E3/TR13 provides 268V maximum clamping voltage compared to 243V in other substitutes. This higher clamping voltage may be beneficial in applications with tighter voltage regulation requirements or where lower clamping voltage is critical. Selection depends on specific circuit protection thresholds.

Q: Why is SMAJ154A-TR not recommended as a substitute?

A: SMAJ154A-TR has a 154V reverse standoff voltage, which differs from the SMAJ150's 150V specification. This voltage difference affects the device's protection threshold and makes it unsuitable for direct substitution in circuits designed for 150V standoff protection.

Q: Are all substitute parts available in Tape & Reel packaging?

A: Yes. All recommended substitute parts are supplied in Tape & Reel (TR) packaging, maintaining compatibility with automated assembly processes.

Q: What is the significance of the operating temperature range differences?

A: SMAJ150A-TP operates from -55°C to 175°C, providing the widest temperature range among substitutes. This extended upper temperature limit is advantageous for applications in high-temperature environments. Other substitutes operate within -50°C to -65°C minimum and 150°C maximum ranges, suitable for standard industrial applications.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All recommended substitute parts are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity level, meeting current environmental and reliability standards.