Is there a pin-compatible replacement for SMAJ28A?

Yes, since SMAJ28A is a standard part number, versions from other manufacturers are designed to be pin-compatible replacements. They share the same DO-214AC (SMA) package and 2-pin configuration.

What risks should I check before replacing SMAJ28A?

Before replacing SMAJ28A, you must check three key risks: 1) Package mismatch, as parts like SMBJ or SMCJ series will not fit. 2) Standoff voltage mismatch, which can damage your circuit or fail to protect it. 3) Peak current and power ratings, to ensure the replacement can handle expected surges.

SMAJ28A Alternatives, Datasheet & Cross Reference | Microdiode Semiconductor (Shenzhen) Co., Ltd.

The SMAJ28A is a popular 400W unidirectional Transient Voltage Suppressor (TVS) diode in a compact DO-214AC (SMA) package. It is designed to protect sensitive electronics from voltage transients by clamping voltages above its 28V standoff rating.

AI replacement insight

Sourcing risklow

The SMAJ28A is widely available from multiple vendors, minimizing sourcing challenges.

Electrical riskhigh

Using a part with a different voltage (e.g., SMAJ26A or SMAJ33A) is high-risk and requires careful engineering validation.

Package riskhigh

Parts from other series (e.g., SMBJ, SMCJ) have different package sizes and are not drop-in replacements.

Can it be replaced directly?

Yes, the SMAJ28A is a multi-sourced part. You can find pin-compatible versions from manufacturers such as Bourns, Littelfuse, and SMC Diode Solutions that serve as direct replacements.

Best replacement path

The best replacement path is to use an SMAJ28A from another reputable manufacturer like Bourns or SMC Diode Solutions, as it offers identical performance and package.

Main risk

The main risk when substituting is selecting a part with an incorrect standoff voltage (Vrwm), which can either fail to protect the circuit or interfere with normal operation.

Recommended alternatives

A pin-compatible alternative from a different manufacturer with identical key electrical and package specifications.

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Alternative comparison matrix

Feature / factor	SMAJ28A	SMAJ28A	SMAJ26A	SMAJ33A	Compatibility / risk
Package	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA) — Package is identical, ensuring form and fit.; SMAJ26A: Package is identical.; SMAJ33A: Package is identical.
Voltage	28.0V	28.0V	26.0V	33.0V	28.0V / 26.0V / 33.0V — Standoff voltage matches, providing correct protection level.; SMAJ26A: Lower standoff voltage may cause clamping during normal operation.; SMAJ33A: Higher standoff voltage may not protect circuits designed for 28V.
Power	400.0W	400.0W	-	400.0W	400.0W — Peak pulse power rating is identical.; SMAJ33A: Peak power rating is identical.
Current	8.8A	8.8A	9.5A	7.5A	8.8A / 9.5A / 7.5A — Peak pulse current rating matches.; SMAJ26A: Higher peak current handling is an improvement.; SMAJ33A: Lower peak current handling capability.
Polarity Or Type	Unidirectional	Unidirectional	-	-	Unidirectional — Polarity is identical.

Application & sourcing insights

Questions & answers

The best alternative to an SMAJ28A is another SMAJ28A from a different manufacturer like Bourns, Littelfuse, or SMC Diode Solutions. These are typically pin-compatible and have identical electrical specifications.