600 V, 11 A N-channel MOSFET in TO-220
At 5.5 A the drop is about 2.1 V, so the dissipation in the channel is roughly 11.5 W at that point — well within the 110 W package limit, but the junction temperature rise from that alone is significant if the duty cycle is high. Input capacitance is 580 pF at 100 V drain-source, which keeps the switching losses manageable in a 50–100 kHz hard-switched converter.
Junction temperature range and package
The TO-220 package is a through-hole workhorse — easy to heatsink, reworkable with a standard soldering iron or hot-air station, and the tab is the drain.