PCMCIA power switch — 4 high-side outputs, 1 A each
The Texas Instruments TPS2224APWPR is a PCMCIA power-distribution switch array with four high-side outputs, each rated for 1 A continuous. It handles the three voltage rails required by PCMCIA and CardBus slots — 3.3 V, 5 V, and 12 V — with a typical on-resistance of 95 mOhm per channel. A serial interface controls the output configuration (3:4 input-to-output ratio), and a status flag reports fault conditions. Built-in fixed current limiting and over-temperature protection eliminate the need for external sense resistors or comparators.
At 1 A per channel, the 95 mOhm typical on-resistance drops about 95 mV and dissipates 95 mW per output.
The serial interface selects the output voltage per slot, and the 3:4 input-to-output ratio allows one input to power multiple outputs with independent control.