4-output PCMCIA power switch — 95 mOhm path, 3:4 mux
The Texas Instruments TPS2223APWPRG4 is a PCMCIA power switch array integrating four high-side outputs with a 3:4 input-to-output ratio, meaning three supply inputs (3.3V and 5V rails) are selectively routed to four output channels for powering PCMCIA or CardBus slots. Each output is rated for 1 A continuous with a typical Rds(on) of 95 mOhm, keeping conduction losses low enough that the 24-HTSSOP exposed-pad package can dissipate the heat without forced airflow in most PCMCIA applications. The serial interface controls output sequencing, and the integrated status flag provides a fault-reporting signal back to the host controller for over-current or over-temperature events.
Protection set — fixed current limit and thermal shutdown
Fault protection includes current limiting (fixed threshold) and over-temperature shutdown — no external sense resistor needed, and the part latches off until the fault clears or the enable is cycled. The status flag output (open-drain, active low) asserts during a fault condition, giving the host controller a direct interrupt signal rather than requiring polling of the output voltage.