Bidirectional clamping at 87.1 V
The 1.5SMCJ54CA-AQ is a unidirectional bidirectional TVS diode — the CA suffix confirms it clamps both polarities, so a single device protects a 54 V rail from both positive transients (load dump, inductive kick) and reverse-polarity events without a second diode. Selecting the standoff at 54 V nominal gives a protection window of roughly 33 V above the rail before clamping engages.
The 1500 W peak pulse rating defines the maximum energy the device can absorb during a single 10/1000 µs transient without failing. In an automotive load-dump scenario — the dominant surge threat in 12 V and 24 V systems — this rating sets whether the diode survives the event or degrades prematurely; a diode undersized for the peak power simply fails short, leaving the protected load exposed.
Automotive temperature grade and SMC mounting
Junction temperature rating extends to 150°C — the upper end of the automotive under-hood band. At 150°C junction, derating is applied per the diode's thermal model, so the actual survivable pulse count drops compared to room-temperature operation. The SMC/DO-214AB package mounts directly to the PCB surface — the clip-lead form factor is not available for this variant (Strip package only). The foot pattern matches the industry-standard SMC footprint, and thermal relief on the landing pad controls the RthJA during clamping events.