200 V, 43 A HEXFET in a D2PAK tab
The IRFS38N20DTRLP is an N-channel HEXFET power MOSFET from International Rectifier, rated for 200 V drain-to-source and 43 A continuous drain current at a 25°C case temperature.
Conduction loss and gate drive budget
At 26 A the conduction loss is 1.4 W per device; double the current to 43 A and the I²R loss climbs to 3.8 W, which is the power dissipation limit at ambient. The gate charge is 91 nC at 10 V — a 100 kHz switching frequency draws 9.1 mA average from the gate driver, well within the capability of a standard driver IC.
Temperature grade and package reality
The D2PAK tab needs a soldered copper area on the PCB to pull heat out; a two-layer board with a 1 oz pour under the tab will handle about 20 A continuous before the junction hits 150°C. The 300 W power dissipation at the case is a theoretical ceiling with an infinite heatsink — real designs stay well below that.
The HEXFET series has been in production for decades; the die technology is mature and the supply base is stable.