The STPS30L120CT is a dual Schottky rectifier from STMicroelectronics, configured as a common-cathode pair in a single TO-220-3 package. Each diode is rated for 120 V reverse voltage and 15 A average forward current, with a maximum forward drop of 880 mV at 15 A. The 120 V reverse rating suits it for 48 V and 72 V DC rails common in telecom rectifiers, industrial power supplies, and motor-drive bus pre-charge circuits. The common-cathode arrangement simplifies center-tap full-wave rectifier layouts — one heatsink tab, one cathode node, two independent anodes.
Forward drop and thermal budget in a TO-220 tab
At 15 A per diode the forward voltage is 880 mV, which sets the conduction loss at about 13.2 W per diode at full load. In a TO-220 package with a properly sized heatsink (thermal pad area under the tab), the junction temperature stays within the 150 °C maximum rating. The fast recovery time — ≤ 500 ns at > 200 mA — is typical for Schottky technology and means the diode recovers without significant reverse-recovery charge, keeping switching losses low in high-frequency rectifier stages.