1500 W peak pulse — what it means for your rail
The 1.5KE91CAH: That 1500 W rating means it can clamp a transient up to 12.6 A peak current without failing — the device absorbs the surge and limits the voltage across your protected circuit to 125 V max. The reverse standoff voltage is 77.8 V, so it sits across a 72 V or 75 V rail without conducting during normal operation. Breakdown starts at 86.5 V minimum, giving a clean trigger threshold before the clamping event.
Automotive-grade transient protection
The axial DO-201AA package (through-hole) handles the thermal dissipation from repeated pulse events better than a surface-mount equivalent.
The DO-201AA (DO-27) axial package requires a 1.0 mm diameter hole in the PCB — typical lead diameter is 0.96 mm. The body length is about 7.5 mm; plan for adequate clearance from adjacent components when mounting vertically or horizontally. Tape & Reel packaging (TR) is standard for automated insertion. The base product number is 1.5KE91 — the 'CAH' suffix denotes bidirectional (CA) and automotive grade (H).