1500W peak pulse — clamping at 70.1V
The 1.5KE51CA-E3/54: The 43.6 V reverse standoff voltage means the diode draws negligible leakage below that rail level, so it sits across a 36 V or 42 V bus without loading it. Breakdown occurs at 48.5 V minimum, giving a narrow guard band between normal operation and clamping — the rail stays protected without nuisance triggering from transients that stay below the standoff.
A single bidirectional channel protects against positive and negative surges, so a single device replaces two unidirectional TVS diodes in back-to-back configuration on AC or bipolar DC lines. The DO-201AA axial-lead package (DO-27 equivalent) is through-hole mounted — the leads handle the thermal pulse of a 1500 W surge without the trace-lift risk of a surface-mount part on a standard FR-4 pad.
The TransZorb series is a Vishay standard for general-purpose circuit protection — no power-line protection rating, so it is intended for signal and DC bus clamping, not AC mains.