Microchip lists the SMBJ30E3/TR13 as Active, so the BOM line is not under end-of-life pressure. No successor has been announced — the part is still the primary offering for this 30V standoff, 600W pulse rating.
600W peak pulse — clamping at 53.5V
Rated for 600W peak pulse power with a 10/1000µs waveform, the SMBJ30E3/TR13 clamps at 53.5V max while conducting 11.2A peak pulse current. The 33.3V minimum breakdown gives a 3.3V guard band above the 30V standoff — enough margin to avoid nuisance triggering on a clean 24V rail but still protect against transients that exceed the rail.
DO-214AA SMB — surface-mount fit
Housed in the DO-214AA (SMB) package, the SMBJ30E3/TR13 is a surface-mount Zener TVS. The SMB footprint is smaller than the SMC but larger than the SMA — it suits boards where the 600W pulse rating demands a bigger junction than an SMA can dissipate, but the layout cannot fit an SMC.