500 V N-channel MOSFET in TO-220 — the switching load envelope
The STP19NM50N is a 500 V drain-source, 14 A continuous-drain N-channel MOSFET from ST's MDmesh™ II series, packaged in a through-hole TO-220-3. These numbers set the gate-driver current requirement: a driver sourcing 1 A can charge the gate in about 34 ns, though the practical switching speed is also limited by the gate-drive loop inductance and the external gate resistor.
Active lifecycle — still a current-production MOSFET
The part is ROHS3 compliant, meeting EU Directive 2011/65/EU and its amendments for lead-free soldering processes. The base product number is STP19, which covers the TO-220 variant in the MDmesh™ II family.
Parametric fit — what the ratings mean for the BOM line
The 500 V Vdss and 14 A continuous current cover a wide range of offline power-converter topologies — flyback, forward, half-bridge — where the MOSFET sees the rectified mains plus reflected voltage. Maximum junction temperature is 150 °C. The 110 W power dissipation at the case (Tc) assumes an infinite heatsink; in practice the TO-220 package's junction-to-case thermal resistance (not listed here) drives the derating, so the actual continuous power is limited by the heatsink's thermal impedance and the ambient temperature. Gate threshold voltage (Vgs(th)) is a maximum of 4 V at 250 µA drain current. This is the point where the device just begins to conduct — for a 10 V drive, the gate overdrive is 6 V, which keeps the Rds(on) in the specified range. The ±25 V maximum gate-source rating gives margin for ringing on the gate node in a hard-switching converter.