What the 100 V / 45 A rating means for your power stage
The STP45N10F7: Its 100 V drain-source breakdown gives comfortable margin on 48 V bus converters, 24 V industrial motor drives, and 12 V automotive loads. At 45 A, expect about 36 W dissipation from Rds(on) alone, which the 60 W package limit can cover if the heatsink is sized right.
Through-hole TO-220 — rework and mounting
TO-220-3 package: three leads, metal tab for heatsink, and a mounting hole. The tab is the drain.
The 175°C maximum is higher than the typical 150°C industrial limit, which gives extra headroom in under-hood or engine-bay environments. Input capacitance is 1640 pF at 50 V Vds, which is moderate; the gate driver sees a manageable load for switching frequencies up to around 100 kHz.
For BOM planning, there is no urgency to stockpile or qualify a substitute.
