650 V Trench Field Stop — the switching-loss anchor for 400 V bus designs
The STGWT20H65FB is a 650 V, 40 A Trench Field Stop IGBT from STMicroelectronics, housed in a TO-3P through-hole package. It is specified for hard-switching applications such as motor drives, PFC stages, and induction heating where the 400 V test condition (400 V, 20 A, 10 Ohm, 15 V) directly mirrors the nominal bus voltage.
Switching energy and gate drive budget
Total switching energy at the 400 V / 20 A test point is 77 µJ turn-on and 170 µJ turn-off. The off-loss dominates the thermal calculation — the designer should size the heatsink for the turn-off component, especially at higher switching frequencies. Gate charge is 120 nC at 15 V drive. A typical gate driver delivering 1 A peak can charge the gate in roughly 120 ns; the 30 ns turn-on delay and 139 ns turn-off delay (at 25 °C) are consistent with a moderate-speed IGBT suited to 10–40 kHz operation.