SMAJ400 Transient Voltage Suppressor Equivalent & Substitute Parts

Part Overview

The SMAJ400 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 400V reverse standoff voltage rating with a 680.4V maximum clamping voltage and 600mA peak pulse current capability in a DO-214AC (SMA) package. The SMAJ400 is classified as obsolete, necessitating identification of active equivalent parts that maintain electrical and mechanical compatibility for ongoing production and repair applications.

Substiute Parts

SMAJ400

Littelfuse Inc.In Stock: 1080SMAJ400 Datasheet

Current PartRFQ

SMAJ400A

MeritekIn Stock: 1820SMAJ400A Datasheet

MFR RecommendedRFQ

SMAJ400A

MeritekIn Stock: 1820SMAJ400A Datasheet

MFR RecommendedRFQ

SMAJ400A-TP

Micro Commercial CoIn Stock: 996SMAJ400A-TP Datasheet

MFR RecommendedRFQ

TV04A401J-HF

Comchip TechnologyIn Stock: 25189TV04A401J-HF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMAJ400 is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): 400V
• Voltage - Clamping (Max) @ Ipp: Must not exceed 680.4V
• Current - Peak Pulse (10/1000µs): Minimum 600mA
• Power - Peak Pulse: 400W
• Package / Case: DO-214AC (SMA)
• Type: Zener, Unidirectional (1 channel)
• Mounting Type: Surface Mount

All substitute parts listed maintain the 400V reverse standoff voltage specification and DO-214AC (SMA) package form factor. Clamping voltage values range from 648V to 680.4V, remaining within acceptable operational limits. Peak pulse current ratings range from 600mA to 620mA, meeting or exceeding the original specification. All substitutes are classified as active products with current manufacturing status.

Parameter Comparison

Engineering Selection Recommendations

All three substitute parts (SMAJ400A from Meritek, SMAJ400A-TP from Micro Commercial Co, and TV04A401J-HF from Comchip Technology) are classified as active products with current manufacturing availability, addressing the obsolescence status of the original SMAJ400.

SMAJ400A (Meritek) and TV04A401J-HF (Comchip Technology) both feature 620mA peak pulse current, exceeding the original 600mA specification while maintaining the 400V reverse standoff voltage and 648V clamping voltage. Both are ROHS3 compliant with MSL 1 rating and operating temperature ranges of -55 to 150°C.

SMAJ400A-TP (Micro Commercial Co) maintains the original 600mA peak pulse current specification and extends the operating temperature range to -55 to 175°C. This variant is supplied in Bulk packaging and is available with the highest inventory level among substitutes.

TV04A401J-HF (Comchip Technology) is supplied in Tape & Reel (TR) packaging and maintains the highest inventory availability (25,100 pieces), supporting high-volume production requirements.

All substitute parts maintain electrical equivalence through identical 400V reverse standoff voltage, compatible clamping voltage performance within 648V to 680.4V range, and equivalent or superior peak pulse current ratings. All are packaged in DO-214AC (SMA) form factor with surface-mount compatibility.

Frequently Asked Questions (FAQ)

Q: Can SMAJ400A (Meritek) be used as a direct replacement for SMAJ400 (Littelfuse)?

A: Yes. Both devices maintain 400V reverse standoff voltage, DO-214AC (SMA) package form factor, and equivalent electrical performance. SMAJ400A features 620mA peak pulse current compared to the original 600mA specification, providing enhanced current handling capability. Clamping voltage is 648V versus the original 680.4V, representing improved voltage regulation performance.

Q: What is the difference between SMAJ400A-TP and SMAJ400A?

A: Both maintain identical electrical specifications (400V reverse standoff, 648V clamping voltage). SMAJ400A-TP is supplied by Micro Commercial Co in Bulk packaging with extended operating temperature range (-55 to 175°C versus -55 to 150°C). SMAJ400A is supplied by Meritek with standard temperature range. Selection depends on packaging requirements and thermal operating environment.

Q: Is TV04A401J-HF compatible with the original SMAJ400 circuit design?

A: Yes. TV04A401J-HF maintains the 400V reverse standoff voltage specification, DO-214AC (SMA) package, and equivalent electrical performance. The device is supplied in Tape & Reel (TR) packaging format suitable for automated assembly processes. Peak pulse current is 620mA, exceeding the original 600mA specification.

Q: What are the compliance differences between substitute parts?

A: SMAJ400A (Meritek) and TV04A401J-HF (Comchip Technology) are both ROHS3 compliant with MSL 1 rating. SMAJ400A-TP (Micro Commercial Co) compliance specifications are not provided in the available data. All three parts carry REACH Unaffected status where specified.

Q: Which substitute part should be selected for high-volume production?

A: TV04A401J-HF (Comchip Technology) offers the highest inventory availability (25,100 pieces) and is supplied in Tape & Reel (TR) packaging, optimizing automated assembly processes. SMAJ400A-TP (Micro Commercial Co) provides the second-highest availability (985 pieces) with extended temperature range capability.

Q: Are there temperature range limitations when substituting the SMAJ400?

A: The original SMAJ400 operates from -65 to 150°C. All substitute parts operate from -55 to 150°C, representing a reduced lower temperature limit of 10°C. SMAJ400A-TP extends the upper limit to 175°C. Applications requiring operation below -55°C require evaluation against the original SMAJ400 specification.