43.6 V standoff, 70.1 V clamp — the protection window for a 48 V bus
The 1.5KE51CA: Its 43.6 V reverse standoff voltage sits just below the nominal 48 V rail, so it does not conduct during normal operation. That clamping ceiling is the voltage the downstream circuitry must survive. No power line protection feature is built in (the part is a standalone transient suppressor, not a filtered protector).
175 °C junction rating — fits underhood and industrial high-temp slots
The -55 °C to 175 °C operating junction temperature range covers the full automotive underhood profile (AEC-Q101 qualified parts in this family share the same die capability) and industrial enclosures near motors or furnaces. Packaged in a DO-201AA / DO-27 axial-lead through-hole body (supplier device package DO-201). The axial leads suit point-to-point wiring in power supplies, motor drives, and industrial controllers where board space is not the constraint. Available in Tape & Reel for automated insertion or Cut Tape for prototype builds.
Active production — no lifecycle risk for new designs
Sourced through independent distribution channels.