Obsolete — BOM-fit check before committing
The 1.5KE16C-E3/73: The 1.5KE16C-/73 is listed as Obsolete by Vishay. For a replacement, the functional spec — 1500W peak pulse power, 12.9V reverse standoff, 23.5V clamping at 63.8A (10/1000µs) — is the starting point. A pin-compatible alternative in the same DO-201AA package with matching bidirectional clamping voltage and surge rating would be the closest drop-in.
What the key ratings mean for the BOM line
The 12.9V reverse standoff voltage means the protected rail can run at 12V nominal without the diode conducting in standby — it only clamps when the transient exceeds the 14.4V minimum breakdown threshold. That clamping ceiling is the voltage the downstream circuit must survive during a surge event — a 24V-rated rail or a 30V-capable DC-DC converter input would have margin here.
Package and deployment context
Housed in a DO-201AA (DO-27) axial-leaded through-hole package, the 1.5KE16C-/73 mounts into a standard 0.100-inch pitch PCB hole pattern. The axial leads handle the thermal cycling of repetitive surges better than small surface-mount packages — suited for industrial power supplies, telecom line cards, or automotive load-dump protection where board space allows leaded parts. Operating temperature range from -55°C to 175°C covers engine-bay and outdoor enclosure environments. The bidirectional single-channel configuration protects a single signal or power rail against both positive and negative transients without needing two diodes back-to-back.