30V rail clamp in a DO-214AA footprint
The SMBJ30A-13: Its 30V reverse standoff voltage means the device does not conduct at normal operating levels up to that DC bias — it stays invisible to the circuit until a surge pushes the line above the 33.3V minimum breakdown threshold. At that point the Zener avalanche structure fires and holds the clamp at 48.4V maximum while shunting 12.4A of peak pulse current (, 10/1000µs waveform).
Active lifecycle and sourcing posture
The SMBJ30A-13 is listed as Active — Diodes Incorporated continues to manufacture the part. The base product number is SMBJ30, so this -13 suffix variant is the tape-and-reel / cut-tape packaging option.