What this switch does on your rail
The TCK22925G,LF is a single-channel P-channel high-side load switch from Toshiba, rated for 2 A continuous output across a 1.1 V to 5.5 V load voltage range. The 25 mOhm typical Rds(on) keeps conduction losses low — at 2 A the dissipation is about 100 mW, well within the WCSP6E package's thermal budget at 85°C ambient. It integrates a slew-rate controlled turn-on to limit inrush current into capacitive loads, plus reverse-current blocking when the output voltage exceeds the input — the scorch mark on a board trace tells you when that protection was missing.
Housed in a 6-ball WLCSP (6-UFBGA, supplier package 6-WCSPE 0.80x1.2), this is a fine-pitch BGA-style package. The 0.80 mm x 1.2 mm footprint demands a controlled solder-paste stencil and a reflow profile suited to lead-free assemblies — no hand-soldering this one. Surface-mount only. The On/Off interface is non-inverting and requires no external Vcc supply — the switch is self-biased from the load rail, saving a pin on the upstream regulator.