Clamping voltage and pulse current — the protection envelope
The SMCJ54AE3/TR13 clamps at 87.1V maximum when hit with a 17.2A peak pulse current (10/1000µs waveform). That clamp voltage is the ceiling the downstream circuitry sees — if your 54V rail can tolerate an 87V transient for microseconds, this TVS fits.
Peak pulse power and temperature range — where it survives
The operating junction temperature spans -65°C to 150°C, so it stays in spec across avionics cold-soak and under-hood heat soak alike.
Breakdown and standoff voltages — the trip point
Minimum breakdown voltage is 60V; the reverse standoff (working voltage) is 54V typical. On a 48V or 54V bus, the TVS stays out of conduction during normal operation but fires before the rail exceeds the downstream switch or controller absolute maximum.
Microchip lists the SMCJ54AE3/TR13 as Active with no EOL or NRND flag. Sourced per RFQ against your BOM quantity.