10 A per diode, 45 V reverse — the power rail sizing number
The RBQ10T45ANZC9: That 10 A per leg sets the continuous current ceiling for the output rail — two diodes in one package share the load in a center-tap or half-bridge topology, so the total package handles up to 20 A in a two-diode forward path. Forward voltage is 650 mV typical at 5 A, which defines the conduction loss floor for thermal design. At 10 A per diode the Vf will be higher — budget the junction temperature rise from the TO-220FN package's thermal resistance to the heatsink tab.
Low reverse leakage and switching speed
Reverse leakage is specified at 70 µA at 45 V — the part description flags this as a low-IR variant, meaning it holds leakage well below the typical Schottky curve at rated voltage. The fast-recovery rating (≤500 ns, >200 mA Io) confirms this is a switching diode, not a 50/60 Hz line rectifier. The 500 ns recovery ceiling is adequate for 100-200 kHz SMPS designs; above that frequency the reverse-recovery charge starts to dominate switching loss.
TO-220FN — fully isolated, no pad isolation needed
The TO-220-3 Full Pack (also called TO-220FN) is a fully molded, isolated package — the metal tab is encapsulated, so no insulating pad or washer is required between the device and the heatsink. This simplifies assembly in through-hole power stages where the heatsink is chassis-grounded or shared across multiple devices. The junction temperature limit is 150 °C. With the full-pack package's higher thermal resistance compared to a standard TO-220, the actual current derating at elevated ambient temperature is steeper — confirm the junction temperature at your operating point before committing the BOM.
ROHS3 compliant, so it meets the current EU restriction directive without exemption expiry concerns.