The RB228NS-30TL: The exposed tab on the D²Pak is the common cathode — the thermal pad on the PCB must connect to the output rail and carry the heat from both diodes. The dual-diode common-cathode configuration fits center-tapped full-wave rectifiers and OR-ing arrays where the two anodes connect to separate AC or supply legs and the common cathode ties to the output bus.
Switching speed and conduction loss
Rated Fast Recovery ≤500 ns at >200 mA — this is a line-frequency rectifier, not a high-speed switching diode. For 50-60 Hz rectification the recovery time is irrelevant; for a 100 kHz boost converter the stored charge will cause significant reverse-recovery loss. Forward drop is 720 mV maximum at 15 A per diode — the conduction loss at half-rated current is 10.8 W per diode. At 30 A the Vf will be higher; the junction temperature must stay within the 150°C limit, which demands a low-thermal-resistance board layout with adequate copper area on the cathode tab. Reverse leakage is 10 µA at 30 V — this off-state current doubles roughly every 10°C above 25°C. At 125°C junction the leakage can reach several milliamps, adding to the thermal budget in elevated-temperature environments.