1500W peak pulse power — the transient budget
That 1.5 kW rating is the energy-absorption ceiling for a single transient event — if the surge exceeds it, the diode short-circuits and the board trace or downstream IC takes the hit. The 26V reverse standoff voltage means the diode stays off below 26 V, drawing negligible leakage. Above that, the breakdown kicks in at 28.9 V minimum, clamping the transient to 53.5 V maximum at the rated peak pulse current of 187 A (8/20µs waveform). That clamp voltage is what the protected IC sees — make sure the downstream part's absolute-max rating is above 53.5 V.
Package and temperature — field-fit check
Housed in a DO-214AB (SMC) surface-mount package, the SMCJ26A-TR is a standard footprint that reflow-solders without special profile tweaks. The unidirectional channel handles positive transients; for AC or bidirectional rails, a bidirectional variant from the same SMCJ family would be the pick.