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STMicroelectronics SMBJ30A-TR — Circuit Protection

STMicroelectronics SMBJ30A-TR TVS Diode, 30 V Standoff

MPNSMBJ30A-TR
Active

STMicroelectronics SMBJ, TRANSIL™ series, TVS Zener diode, unidirectional, 30 V reverse standoff, 33.3 V breakdown, 48.4 V clamping, 600 W peak pulse power, DO-214AA (SMB) surface mount, -55 to 150 °C.

$0.4500Ref. price · indicative, final on quote
STMicroelectronics SMBJ30A-TR datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

SMBJ30A-TR specifications
ParameterValue
TypeZener
SeriesSMBJ, TRANSIL™
MountingSurface Mount
Voltage - breakdown33.3V
Voltage - clamping (Max) @ ipp48.4V
Voltage - reverse standoff30V
Current - peak pulse (10/1000μs)13A
Power - peak pulse600W
Power line protectionNo
Operating temperature-55°C~150°C(TJ)
PackageTape & Reel (TR); Cut Tape (CT)
ApplicationsGeneral Purpose
CaseDO-214AA, SMB
Unidirectional channels1

Product details

30 V standoff, 600 W pulse — the protection threshold that matters

Its 30 V reverse standoff voltage matches the nominal voltage of a 24 V or 28 V bus, so the diode stays out of conduction during normal operation and only shunts overvoltage events.

Clamping voltage and breakdown — the margins that protect downstream silicon

When the diode fires, it clamps at a maximum of 48.4 V while conducting a peak pulse current of 13 A. The minimum breakdown voltage is 33.3 V, so the protection window is tight: the rail sees no clamping below 33.3 V, and the clamp holds at 48.4 V worst-case. For a 24 V rail feeding a regulator rated at 60 V, that leaves comfortable headroom.

Package and mounting — DO-214AA (SMB) surface mount

The SMBJ30A-TR comes in the DO-214AA (SMB) package, a standard surface-mount footprint shared across the SMBJ family. Cut Tape (CT) is also available for prototype or low-volume builds.

Frequently asked questions

Is SMBJ30A-TR unidirectional or bidirectional?

It is a unidirectional device with one channel. For bidirectional protection on AC or bipolar lines, you would need two back-to-back unidirectional TVS diodes or a dedicated bidirectional part.

What is the peak pulse power rating of SMBJ30A-TR?

The peak pulse power rating is 600 W for a 10/1000 µs waveform. This defines the surge energy the diode can absorb in a single pulse event.

Can SMBJ30A-TR replace SMBJ30A?

Yes — the SMBJ30A-TR is the same die as the SMBJ30A, just in Tape & Reel packaging. The base product number is SMBJ30, and the -TR suffix is the packaging variant. Electrically identical.