98 mOhm Rds(on) at 3 A — the P-channel load-switch workhorse
The Infineon IRLML5203TRPBF is a P-channel HEXFET MOSFET in a SOT-23-3 package, rated for 30 V drain-source and 3 A continuous drain current. With a 14 nC total gate charge at 10 V, this part can be driven directly from a microcontroller GPIO through a series resistor — no dedicated gate driver needed for moderate switching frequencies. The 1.25 W power dissipation in the SOT-23 package is the thermal ceiling; at 3 A continuous, the actual dissipation at 98 mOhm is about 0.9 W, leaving some headroom before you hit the package limit.
30 V Vdss and -55 to 150 °C — headroom for harsh environments
The 30 V drain-source rating gives comfortable margin on a 12 V rail (2.5× derating) and reasonable margin on a 24 V industrial bus (1.25×). For a 28 V aerospace bus, the headroom is tight — you would want to check the transient voltage spikes on your rail before committing. Gate threshold voltage is 2.5 V max at 250 µA drain current. The recommended minimum drive voltage is 4.5 V.
SOT-23-3 — field-swappable with a standard iron
The SOT-23-3 package (Micro3/SOT-23) is a standard small-signal footprint. You can hand-solder this with a fine-tip iron and some flux; no hot-air station needed for a field repair. The part is also available in cut tape for small-quantity prototyping.
It is ROHS3 compliant.