What the 1500 W peak pulse rating means for your rail
The 1.5KE22A R0G: For a shorter pulse (8/20 µs), the same die can absorb a higher peak current, but the 10/1000 µs figure is the one that governs the part's placement in a protection budget.
Clamping voltage and breakdown: the protection window
The reverse standoff voltage is 18.8 V — the rail voltage below which the diode draws negligible leakage. This means a 24 V bus or a 18 V regulated supply sees the diode as an open circuit until a transient pushes the line above 20.9 V; the clamp then holds the spike to 30.6 V, protecting downstream silicon rated for, say, 36 V abs-max.
DO-201 axial package and board integration
The DO-201AA (DO-27) axial-lead package is a through-hole form factor with a body diameter of about 5.3 mm and a lead diameter of 1.3 mm. It mounts into a 1.1 mm hole on a standard PCB or terminal block. The axial leads carry the full 51 A surge current — the trace width feeding each lead should be sized for that peak current, not the DC load. The package is rated for junction temperatures from -55 °C to 175 °C, covering industrial and automotive under-hood ambient ranges.