8 mOhm Rds(on) — the thermal budget anchor
The Texas Instruments TPS1HA08CQPWPRQ1 is an automotive-grade, AEC-Q100 qualified high-side power switch with a single N-channel output rated for 20 A continuous current. The 8 mOhm typical on-resistance is the figure that sets the conduction loss — at 10 A load, expect about 0.8 W dissipation before accounting for temperature rise. That 8 mOhm is specified at 25°C junction; at 125°C the Rds(on) roughly doubles, so the thermal design needs headroom for the hot-case condition.
Load voltage and fault protection
The switch operates with a load supply from 8 V to 18 V, covering the 12 V automotive bus with margin for cranking and load-dump transients. Fault protection includes adjustable current limiting, open-load detection, over-temperature shutdown, and UVLO — these are the diagnostics that let an ECU detect a shorted or disconnected actuator without a separate sense circuit.
Housed in a 16-lead HTSSOP (PowerTSSOP) with an exposed pad for heat sinking. The inverting input type means the switch turns on when the logic input is low — confirm the polarity against the MCU GPIO drive.
For long-run BOM planning, this is a current-production part with standard supply-chain availability through independent distribution.