Protection rail fit — 45V standoff, 72.7V clamp
The SMBJ45CA-13: The clamp engages at 72.7V maximum, shunting 8.3A of surge current (10/1000µs waveform) and absorbing 600W of peak pulse power. Because it is bidirectional, a single device protects both polarities on AC lines or bipolar DC rails — no need for two diodes back-to-back. The 45V standoff also covers 36V and 48V nominal rails with margin for steady-state tolerance.
Package and board-fit — DO-214AA SMB
The SMB body is larger than the SMA sibling, which means lower thermal resistance to the board copper for sustained pulse trains.
Sourcing reality — active line, quoted per reel
The base product number SMBJ45 covers the full voltage family, so the production line runs continuously for the whole SMBJ series. Supplied in Tape & Reel (TR) or Cut Tape (CT) — the reel quantity is the standard SMBJ reel count. For volume BOM positions, the per-unit cost lands below the cut-tape price break; quoted to order against the reel MOQ.