34 mOhm switch with full protection set
The NXP NX5P3090UKZ is a single-channel, high-side USB power switch in the NX5 series. Its 34 mOhm typical on-resistance keeps conduction losses low at the 3.3 A maximum continuous output, making it suitable for USB charging ports and general-purpose power-rail switching in portable and consumer gear. Protection is comprehensive: adjustable current limiting, overtemperature shutdown, reverse-current blocking, and undervoltage lockout (UVLO) are all integrated. A status flag output reports fault conditions. The input is non-inverting with a simple On/Off interface.
WLCSP footprint and thermal reality
The 12-WLCSP package measures 1.65 x 1.35 mm — tiny, but the 3.3 A rating means the PCB copper and via pattern under the package must handle the dissipation. The 34 mOhm Rds(on) at 3.3 A produces about 370 mW of heat; without adequate thermal vias to a ground plane, the junction temperature will climb quickly at maximum load.