650 V CoolMOS™ — what the ratings mean for the switching stage
The Infineon SPI07N65C3XKSA1 is an N-channel power MOSFET from the CoolMOS™ series. Rated at 650 V drain-to-source and 7.3 A continuous drain current at 25°C case temperature, it targets the primary switching stage of offline AC-DC converters, power-factor-correction (PFC) boost stages, and flyback topologies. The 600 mOhm maximum on-resistance at 10 V gate drive sets the conduction loss budget; with 27 nC typical gate charge, the driver sees a light capacitive load. The TO-262-3 (PG-TO262-3-1) through-hole package suits wave-soldered boards where a heatsink can be bolted to the tab.
Gate-drive and switching behaviour
The 10 V gate-drive level for the rated Rds(on) is standard for CoolMOS™; the ±20 V absolute maximum gate-source voltage gives headroom for ringing on a hard-switched node. The 790 pF input capacitance at 25 V drain bias translates to a moderate switching loss. For soft-switching topologies (LLC, phase-shifted full bridge) the 27 nC gate charge keeps the circulating energy manageable.
Thermal budget and mounting
The 83 W maximum power dissipation at case temperature assumes a heatsink held at 25°C — in practice, the junction-to-case thermal path through the TO-262 tab needs a properly greased or pad-insulated heatsink. The -55°C to 150°C junction temperature range covers cold-start in outdoor telecom cabinets and full-load thermal cycling in enclosed power supplies. The through-hole mounting (PG-TO262-3-1) is a three-lead I²Pak-compatible footprint; the centre drain tab is the primary heat path, so the PCB copper area under the tab matters less than the heatsink interface.