1.5 kW bidirectional Zener TVS in DO-201AA
The 1.5KE51C-E3/73: It clamps transients at 73.5 V maximum while conducting 20.4 A peak pulse current, protecting downstream circuits from surges on 41.3 V nominal rails.
Voltage ratings and protection window
Reverse standoff voltage is 41.3 V typical, meaning the diode draws negligible leakage below that rail level. Breakdown occurs at a minimum of 45.9 V, and clamping is guaranteed at 73.5 V maximum at the rated peak current — a 32 V window from standoff to clamp that keeps the protected bus within safe limits during a surge. The bidirectional configuration (single channel) protects both polarities, so a single part covers positive and negative transients on AC or DC lines without needing two back-to-back unidirectional devices.
Thermal and mechanical envelope
The DO-201AA (DO-27) axial-lead package mounts through-hole, suited for point-of-use transient suppression on power entry boards or terminal blocks.
Lifecycle status and sourcing
Vishay lists the 1.5KE51C-/73 as obsolete.