1500 V N-Channel MOSFET in a TO-220
The STP3N150 is a 1500 V N-channel PowerMESH MOSFET from STMicroelectronics in a TO-220 through-hole package. With a continuous drain current of 2.5 A at 25°C case temperature and a maximum on-resistance of 9 Ohm at 1.3 A with 10 V gate drive, this part targets high-voltage power conversion applications where primary-side switching and flyback topologies are common.
Gate drive and switching considerations
Input capacitance is 939 pF at 25 V drain-source — this is the Miller plateau region the driver must charge. The ±30 V maximum gate-source rating provides good noise margin in noisy power environments, but the gate threshold is specified at 5 V maximum with 250 µA drain current, so a 10 V gate drive (as used for the Rds(on) spec) is recommended to fully enhance the channel and minimize conduction losses.
Thermal and mounting
In a TO-220 package, the metal tab must be soldered or clamped to a heatsink with thermal compound — the tab is electrically connected to the drain, so an insulating pad or mica washer is needed if the heatsink is grounded. Operating temperature is specified as 150°C junction, which covers most industrial environments but requires derating above 25°C case temperature.