800 V N-channel in a TO-220 — the switching-loss envelope
The STP7N80K5 is an 800 V, 6 A N-channel MOSFET from STMicroelectronics' SuperMESH5™ series, housed in a TO-220-3 through-hole package. The 800 V drain-source rating places it in offline flyback converters, power-factor-correction stages, and high-voltage DC-DC converters where the bus voltage can exceed 400 V with margin for transients. At 6 A continuous drain current, the conduction loss at 25°C junction is 43 W — well within the 110 W power dissipation rating of the TO-220 package when mounted on an adequate heatsink.
Gate charge and drive requirements
Total gate charge is 13.4 nC at Vgs = 10 V. This low Qg allows direct drive from a PWM controller output without a separate gate driver, simplifying the BOM in cost-sensitive power supplies. The input capacitance Ciss is 360 pF at Vds = 100 V, which sets the switching loss ceiling at high frequency. Gate threshold voltage is 5 V maximum at Id = 100 µA.
Temperature range and reliability screening
This makes the STP7N80K5 suitable for satellite power supplies, downhole instrumentation, and engine-bay power stages where the ambient temperature exceeds 85°C.