Breakdown and standoff margins
The 1.5SMC43A-E3/57T: The minimum breakdown voltage is 40.9V, with a reverse standoff of 36.8V — the rail sits 4.1V below the breakdown knee under normal conditions, giving margin for ripple and DC tolerance without leakage. The 1500W peak pulse power means it can absorb a 25.3A surge for the standard 10/1000µs waveform before the junction temperature hits the limit. The DO-214AB (SMC) package is surface-mount, with the cathode band marking the unidirectional orientation.