What the 45 mOhm Rds(on) means for your load budget
The IPS031 is a single-channel low-side N-channel power switch from Infineon, packaged in a TO-220-3 (TO-220AB) through-hole package. Its 45 mOhm typical on-resistance at 25°C sets the conduction loss floor: at 3.1 A continuous output the dissipation is roughly 0.43 W before any derating. That number climbs with junction temperature — the datasheet's normalised curve is the real thermal anchor, not the room-temperature typical.
Fault protection that saves external components
Fixed current limiting and over-temperature shutdown are built in — no external sense resistor or thermal sensor needed. The input is a simple On/Off non-inverting logic signal; no Vcc supply is required, so the switch can be driven directly from a GPIO or a relay coil driver.
Temperature grade — wider than typical industrial
The TO-220 package with a copper tab lets you bolt it to a heatsink or chassis — the thermal pad area under the tab sets the junction-to-case resistance.
Obsolete — sourcing reality and what to do
Infineon lists the IPS031 as Obsolete.