The TPS2220ADB is a triple high-side power switch from Texas Instruments designed specifically for PCMCIA card slots. It integrates three independent outputs — one for VCC and two for VPP — each capable of delivering up to 1A continuous. The switch handles the three standard PCMCIA supply rails (3.3V, 5V, and 12V) and is controlled via a serial interface. A status flag output reports fault conditions, and built-in fixed current limiting plus over-temperature shutdown protect both the host and the card from overcurrent events.
The 95 mOhm typical Rds(on) sets the conduction loss floor: at 1A per output, each channel dissipates roughly 95 mW in the switch, which sums to under 300 mW for all three outputs — manageable in the 24-SSOP package without airflow, but the board copper area under the package matters for thermal spreading. The 1:1 input-to-output ratio means each output is independently gated by the serial interface — there is no sequencing logic on-chip; the host controller must manage the power-up and power-down sequence per the PCMCIA specification. Fault protection is fixed — the current limit threshold is not adjustable, and the over-temperature shutdown is non-latching (auto-retry). If the application needs a latched shutdown or an adjustable current limit, a different switch family is required.