SiC Schottky — zero-recovery switching for high-voltage rails
The STPSC5H12D is a silicon-carbide Schottky diode from ST's ECOPACK®2 series, rated 1200 V reverse and 5 A average rectified current. Its zero reverse recovery time (0 ns trr) eliminates the switching losses that plague ultrafast silicon diodes in hard-switched topologies — no recovery charge to extract, no tail current.
The 1200 V blocking voltage covers 400 VAC rectified rails (≈560 VDC) with margin for switching overshoot, and even 800 VDC bus architectures common in 3-phase industrial drives and EV charging stations. The 5 A average rating is the thermal current limit at Tc=100°C — in a continuous-conduction-mode PFC the RMS current is higher than the average, so the designer sizes the heatsink for the conduction loss at the forward voltage of 1.5 V at 5 A. The 450 pF junction capacitance at 0 V is low enough that the capacitive turn-on loss at a few hundred kHz stays manageable.
175°C junction — thermal headroom for tight enclosures
The 175°C upper limit allows the junction to ride through overload transients without immediate derating, and it simplifies heatsink design in sealed or fanless power supplies where the ambient inside the enclosure can reach 85-100°C. The 30 µA reverse leakage at 1200 V and 25°C is typical for a 5 A SiC Schottky; at 175°C the leakage rises, but the zero-recovery characteristic keeps the switching loss near zero, so the total die temperature stays lower than an equivalent ultrafast silicon diode under the same load.