The TPS22901YFPR is a single-channel P-channel load switch from Texas Instruments, designed for general-purpose power gating in low-voltage rails. The slew-rate controlled turn-on limits inrush current, which is useful when powering capacitive loads like sensor modules or RF front-ends that would otherwise droop the supply rail. The part is controlled by a digital On/Off input (non-inverting), and requires no external Vcc supply — the gate drive is derived from the input voltage. This makes it a simple drop-in for battery-powered or portable designs where every microamp of quiescent current matters.
Sizing the switch for your rail
The 4-DSBGA package (0.8 mm x 0.8 mm typical) is tiny — great for space-constrained PCBs, but the 0.5 mm ball pitch means hand-soldering is tricky. A reflow profile with a stencil is recommended; for prototyping, a hot-air station with fine tip and flux works if you're careful. The package is ROHS3 compliant.