On-resistance and gate charge — the switching-loss trade-off
Rds(on) of 15 Ohm at Vgs=10 V and 400 mA is specified at 25 °C junction; actual on-resistance rises with temperature per the normalised curve in the datasheet.
Package and thermal — SOT-223 layout notes
The SOT-223 package (TO-261-4) is a surface-mount footprint with a large copper pad on the tab side for heat sinking. Maximum power dissipation is 3.3 W at case temperature.
