500 V, 14 A switching — conduction loss and drive budget
The STP14NK50Z is an N-channel 500 V, 14 A MOSFET from STMicroelectronics' SuperMESH™ series, housed in a TO-220 through-hole package. The 500 V drain-source rating (Vdss) suits it for offline flyback converters, 3-phase motor drive bus rails, and auxiliary power supplies where the DC link sits at 380 V or higher. Total gate charge (Qg) is 92 nC at 10 V. A gate driver sourcing 1 A charges the gate in roughly 92 ns, setting the practical switching frequency ceiling — above 100 kHz the gate drive loss (Qg × Vgs × fsw) becomes a significant fraction of the 150 W package dissipation limit.
Input capacitance (Ciss) is 2000 pF typical at 25 V drain-source. This capacitance, together with the gate charge, determines the switching energy per cycle — in a hard-switched topology the Coss losses scale with Vds² and frequency, so the 2000 pF figure feeds into the loss budget at the design stage. Maximum gate-source voltage is ±30 V, providing margin against drive overshoot in circuits where the gate drive transformer or bootstrap supply rings during switching transitions.
Lifecycle and compliance status
RoHS compliance is confirmed at the ROHS3 level, covering the ten restricted substances including the four phthalates added under EU 2015/863.