Automotive-grade transient protection
The 1.5SMBJ78A-H: AEC-Q101 qualification means this part meets the stress and reliability tests required for automotive electronics — the OEM auditor will expect PPAP documentation, and Bourns provides it. Clamping at 126 V maximum (at Ipp 11.9 A) keeps the downstream rail within the safe operating area of typical 100 V-rated ICs, with a 78 V reverse standoff that leaves margin on a nominal 48 V or 60 V bus.
DO-214AA (SMB) surface-mount package — the same footprint as many standard TVS diodes, so a layout already using SMB for other rail protection needs no copper-pattern change.