Clamping specs for a 36.8 V rail
The 1.5KE43CA/54: Its 36.8 V reverse standoff voltage means it sits across a nominal 36 V DC bus and stays out of the way until a transient pushes the line above 40.9 V breakdown, then clamps at 59.3 V while shunting 25.3 A peak pulse current. That 59.3 V clamp ceiling is the number to check against the downstream device's abs-max rating — if the protected IC can survive 60 V for the pulse duration, this part fits. The bidirectional construction means a single device guards both polarities, useful on AC-coupled signal lines or floating DC rails where the return isn't grounded.
Obsolete — sourcing through surplus channels
Vishay lists the 1.5KE43CA/54 as obsolete.
Through-hole axial — hand-solderable and breadboard-friendly
The DO-201AA (DO-27) axial leaded package is a through-hole part — easy to hand-solder, fits standard 0.100-inch pitch perfboard, and the leads can be bent to fit existing PCB layouts. No reflow profile needed, no stencil. Power line protection is not listed — this is a signal- or low-power-rail TVS, not a mains surge suppressor.