The STPS40150CG-TR is a dual Schottky rectifier from STMicroelectronics, pairing two 150 V, 20 A diodes in a common-cathode configuration inside a single D2PAK (TO-263AB) surface-mount package. This is the standard building block for high-frequency output rectification in switch-mode power supplies, OR-ing diodes in redundant power architectures, and freewheeling diodes in motor-drive or inverter stages where the 150 V reverse voltage gives headroom on a 48 V or 72 V bus. Each diode is rated for 20 A average rectified current (Io) and a fast recovery time of ≤ 500 ns at currents above 200 mA — fast enough to keep switching losses manageable in a 50–100 kHz converter without the reverse-recovery snap of a pn-junction diode.
Forward drop and leakage — the thermal budget drivers
At 20 A forward current the maximum Vf is 920 mV. That is the conduction loss floor: at 20 A per diode, the power dissipated in each junction is 18.4 W at the Vf ceiling. The D2PAK's exposed paddle pulls heat into the PCB copper plane — the board layout and copper area under the tab set the junction-to-ambient thermal resistance, not the package alone. Reverse leakage is 8 µA at the 150 V rated reverse voltage. For a 150 V Schottky that is low — it keeps standby dissipation negligible and lets the diode run hotter before leakage current starts to dominate the thermal budget. The maximum junction temperature is 175 °C, so the part can handle brief overloads or high ambient temperatures in enclosed power supplies.