Obsolete — sourcing through independent channels
The 1.5KE91C-E3/73: The 1.5KE91C-/73 is officially obsolete per Vishay's lifecycle status.
What the 1500 W rating means for your protection design
The 73.7 V reverse standoff voltage means it sits across a 72 V or 60 V rail without conducting in normal operation — it only starts clamping when the transient exceeds the minimum breakdown of 81.9 V. At the full 11.5 A peak pulse current, the voltage is clamped to 131 V max, protecting downstream semiconductors rated for that ceiling.
Bidirectional — one device for both polarities
With a single bidirectional channel, this TVS clamps transients of either polarity — useful on AC signal lines or DC rails where the return path can swing negative. The DO-201AA (DO-27) axial-lead through-hole package mounts into a standard 0.100-inch pitch hole pattern; the junction temperature range spans -55°C to 175°C, covering industrial and telecom environments.