The TPS22942DCKRG4 is a single-channel, high-side load switch from Texas Instruments, built around a P-Channel MOSFET with a typical on-resistance of 400 mOhm. That figure defines the voltage drop across the switch at full load — at 100 mA the drop is roughly 40 mV, negligible for most 1.8 V to 5 V rails. The switch operates from a load voltage of 1.62 V to 5.5 V, covering the common logic and peripheral supply levels in portable and embedded designs.
Fault protection set: fixed current limit, thermal, UVLO
The part integrates fixed current limiting, over-temperature shutdown, and undervoltage lockout (UVLO). The current limit is a fixed, non-adjustable threshold — the designer budgets for a 100 mA max continuous output, with the limit acting as a hard ceiling against shorts. UVLO holds the switch off until the input rail is above the threshold, preventing the load from seeing a partially-raised supply. Over-temperature protection folds back the output if the die exceeds the thermal limit, which matters in a small SC-70-5 package with limited copper to sink heat.