1200 V, 50 A fast recovery diode — the TO-220-2 workhorse for hard-switched power stages
The Infineon IDP30E120XKSA1 is a general-purpose fast recovery diode in a TO-220-2 through-hole package, rated for 1200 V DC reverse voltage and 50 A average rectified forward current. It is built with standard planar technology and delivers a reverse recovery time of 243 ns, placing it in the fast recovery class (≤ 500 ns at > 200 mA). Typical applications include boost PFC stages, output rectification in offline flyback converters, snubber clamps, and freewheeling diodes in motor drive inverters where the DC bus is 600–800 V and the switching frequency stays under 50 kHz.
243 ns trr — what it buys in a hard-switched design
The 243 ns reverse recovery time is the key switching parameter. In a continuous-conduction-mode PFC or hard-switched inverter, the diode's reverse recovery charge contributes directly to the turn-off loss in the companion MOSFET or IGBT. A 243 ns trr is typical for a 1200 V fast epitaxial diode — it reduces the recovery spike and the associated EMI compared to a standard recovery part, but it still requires a snubber or careful layout when the switching frequency pushes past 30 kHz. The forward voltage is 2.15 V at 30 A, so conduction loss at full load is around 100 W — the TO-220-2 package needs a heatsink sized for that dissipation, especially at the 150 °C junction temperature limit.
Package and thermal reality — TO-220-2 with the PG suffix
The package is a standard TO-220-2 with the Infineon PG-TO220-2-2 variant — two leads, a metal tab that is electrically the anode (common cathode on the tab), and a 3.2 mm mounting hole for a screw or clip to the heatsink. The junction-to-case thermal resistance is not listed in this evidence, but for a 50 A diode in a TO-220, the tab must be bolted to a heatsink with thermal compound; the 150 °C junction limit is reachable with a few tens of watts of dissipation. The through-hole mounting is straightforward for wave-solder or hand-solder assembly, and the package is widely second-sourced across the industry.