Is there a pin-compatible replacement for SMAJ28CA?

SMAJ26CA is a potential pin-compatible candidate in the same SMA package. However, its lower standoff voltage (26V vs 28V) is a critical difference that must be evaluated for your specific application to avoid unintended clamping.

What risks should I check before replacing SMAJ28CA?

Key risks include: 1) Package mismatch, requiring a new PCB layout. 2) Polarity mismatch (unidirectional vs. bidirectional). 3) Standoff voltage differences; a lower voltage may clamp during normal operation, while a higher one may not protect sensitive components.

SMAJ28CA Alternatives, Datasheet & Cross Reference | BOURNS

SMAJ28CA is a 400W bidirectional TVS diode in an SMA package, protecting circuits with a 28V standoff voltage. Finding a substitute requires matching the package, bidirectional polarity, and standoff voltage.

AI replacement insight

Electrical riskhigh

Standoff voltage is a critical parameter for TVS diodes and must be carefully matched to the application's operating voltage.

Package riskmedium

Some functional alternatives are in different packages (e.g., SMB), which requires a PCB layout change.

Can it be replaced directly?

No direct, drop-in replacement with identical key parameters was found in this review. All viable alternatives have different standoff voltages or packages, requiring engineering validation.

Best replacement path

Cross-reference other manufacturers for an identical SMAJ28CA, or evaluate SMAJ26CA if a 26V standoff voltage is acceptable for the application.

Main risk

The primary risk is electrical incompatibility due to mismatched standoff voltage. A lower voltage may clamp during normal operation; a higher voltage may fail to protect the circuit.

Recommended alternatives

A potential alternative in the same package, but with a lower 26V standoff voltage that requires circuit compatibility review.

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Alternative comparison matrix

Feature / factor	SMAJ28CA	SMAJ26CA	SMBJ36CA	Compatibility / risk
Package	DO-214AC (SMA)	SMA (DO-214AC)	DO-214AA, SMB	SMA (DO-214AC) / DO-214AA, SMB — Package is physically compatible.; SMBJ36CA: Larger package requires PCB redesign.
Polarity Or Type	Bidirectional	Bidirectional	Bidirectional	Bidirectional — Polarity matches target.; SMBJ36CA: Polarity matches target.
Voltage V	28V	26V	36V	26V / 36V — Lower standoff voltage requires circuit review.; SMBJ36CA: Higher standoff voltage may not protect circuit.
Power W	400W	400W	600W	400W / 600W — Power rating matches.; SMBJ36CA: Higher power rating provides more protection.

Application & sourcing insights

Questions & answers

There is no single 'best' alternative. SMAJ26CA is in the same package but has a lower 26V standoff voltage, requiring review. Other parts like SMBJ36CA offer higher power but need a different PCB footprint.