The TPS22941DCKR is a single-channel, high-side P-channel load switch from Texas Instruments, designed to power-rail sequence or isolate loads up to 40 mA continuous. Its load voltage range of 1.62 V to 5.5 V covers 1.8 V, 2.5 V, 3.3 V, and 5 V logic and sensor supplies — no separate Vcc bias rail is needed. With a typical on-resistance of 400 mΩ, the voltage drop at 40 mA is 16 mV — negligible for most downstream circuits, but the 400 mΩ itself sets the self-heating budget: at 40 mA the dissipation is 0.64 mW, well within the SC-70-5 thermal capability even at 125°C ambient.
On-resistance and protection set the BOM fit
The 400 mΩ typical Rds(on) is the dominant spec for BOM conduction loss — compare it against your load current squared. The switch includes fixed current limiting, over-temperature shutdown, and undervoltage lockout, so no external sense resistor or reset supervisor is needed for basic fault protection. The non-inverting On/Off interface accepts logic-level enable signals — the threshold is compatible with 1.8 V and 3.3 V CMOS without a level shifter. The auto-restart feature means the switch attempts to re-enable after a fault clears, which suits battery-powered gear where a latch-off would require a power cycle.
Active production, SC-70-5 footprint
The SC-70-5 package is a 5-lead SOT-353 footprint, 2.0 mm × 1.25 mm body, 0.65 mm pitch. Tape & Reel and Cut Tape options are listed; the base product number is TPS22941 for cross-referencing. ROHS3 compliant.