Obsolete — sourcing path for sustainment
Littelfuse has marked the 1.5KE43C-B as obsolete. No last-time-buy window remains open.
Zener TVS parametrics — what the ratings mean for the board
The 36.8 V reverse standoff voltage is the maximum DC or AC peak voltage the protected line can carry without the device conducting — above that, breakdown begins at 38.75 V minimum. Clamping is specified at 62.27 V maximum when the device conducts 25.6 A of peak pulse current. This clamping voltage is the upper bound the downstream circuitry must survive; a 48 V bus or 36 V rail with a 20 % tolerance stays below the standoff threshold.
Package and board-fit — DO-201 axial leaded
Housed in the DO-201AA / DO-27 axial-lead package, with the supplier device package designated DO-201. Through-hole mounting — the axial leads insert into plated through-holes and are wave-soldered or hand-soldered on the opposite side. The bidirectional configuration uses a single device to clamp both positive and negative transients, saving board space versus two unidirectional diodes back-to-back. No power line protection feature is built in — this is a general-purpose transient suppressor, not a rail-clamp array.