200 V, 4 A Schottky — the conduction loss floor
The STPS4S200S is a 200 V, 4 A Schottky rectifier in the DO-214AB (SMC) package. At its rated 4 A forward current the typical forward voltage drop is 870 mV, which sets the conduction loss at 3.48 W — the thermal pad on the SMC footprint must pull that heat into the board copper or the junction temperature climbs past the 175°C absolute maximum. The fast recovery speed (under 500 ns, above 200 mA) means it handles the reverse-recovery transient in a 100 kHz or higher switching node without the stored-charge tail of a standard PN diode — the Schottky barrier itself eliminates minority-carrier storage, so the recovery is limited by junction capacitance, not carrier lifetime.
Reverse leakage at temperature — the hidden thermal driver
At 200 V reverse bias the maximum leakage is 5 µA at 25°C, but Schottky leakage doubles roughly every 10°C. At 125°C junction the leakage current is in the milliampere range, adding a self-heating term that must be included in the thermal budget — the 175°C junction rating is the hard ceiling, not a comfortable operating point. The SMC package (DO-214AB) has an exposed metal tab on the cathode side. The PCB layout engineer should connect this tab to the output rail with a copper pour area of at least 30 mm² per side to keep the junction-to-ambient thermal resistance below 60°C/W in still air. Without that copper, the 4 A continuous rating derates significantly above 85°C ambient.
Active production, ROHS3 — sourcing posture
The base product number STPS4 covers both the STPS4S200S (SMC package) and the STPS4S200UF (ECOPACK® package variant). The die is the same — the difference is the molding compound and plating finish. For a board already laid out for the SMC footprint, the STPS4S200S is the direct fit; the UF variant requires a different land pattern.