43V rail protection envelope
The SMCJ43CA-13-F: Because it is bidirectional, the same device clamps positive and negative surges symmetrically — one part covers both polarities on a floating signal pair or an AC-coupled line. No power-line protection flag confirms it is designed for signal and low-voltage power rails, not mains-level AC.
Package and board-fit
Housed in a DO-214AB (SMC) package, this is a standard surface-mount footprint shared across the SMCJ series. The SMC package body measures roughly 7.1 mm x 6.2 mm with a 2.6 mm seated height — the same land pattern as other 1500W TVS diodes in this form factor, so a PCB already laid out for a Littelfuse or Vishay SMC part accepts this one without a respin. The 150°C ceiling means derating the peak pulse power above 25°C per the datasheet curve — at 125°C ambient the effective pulse capability drops to roughly 75% of the 1500W rating.
The base product number SMCJ43 covers both unidirectional (SMCJ43A) and bidirectional (SMCJ43CA) variants in the same DO-214AB package. If the BOM calls for the unidirectional version, the SMCJ43A-13-F is the direct sibling; the footprint and power rating are identical.