400 V N-channel switch in a SOT-223 footprint
It is built on Infineon's SIPMOS technology and comes in the PG-SOT223-4-21 surface-mount package. The part is a good fit for auxiliary bias supplies, offline startup circuits, relay and solenoid drivers, and high-voltage signal switching where the load current stays under 170 mA.
On-resistance and gate drive — what 25 Ohm means at 170 mA
Maximum Rds(on) is 25 Ohm at Vgs = 10 V and Id = 170 mA. At 170 mA the conduction loss is I²R = 0.72 W, which sits inside the 1.8 W power dissipation rating at 25 °C ambient. The gate threshold voltage is 2.3 V max at 94 µA, so a 5 V logic-level gate drive will turn the device on, though the specified Rds(on) is measured at 10 V. Gate charge is 5.9 nC at 10 V — a small figure that keeps switching losses low in a 100 kHz flyback converter.
Junction temperature range is -55 °C to 150 °C, covering military and industrial extremes. The 1.8 W power dissipation at 25 °C ambient assumes the SOT-223 copper pad on the PCB is sized per the datasheet layout recommendation — derate above 25 °C. Input capacitance is 154 pF at Vds = 25 V, keeping driver loading light.
The part is ROHS3 compliant.