PCMCIA power-domain switch array
The Texas Instruments TPS2226DBG4 is a four-output high-side PCMCIA power switch array designed to route 3.3 V, 5 V, or 12 V to PC Card slots. Each output is rated for 1 A continuous, with a typical on-resistance of 95 mOhm — low enough to keep voltage drop under 100 mV at full load per channel.
Fault protection — fixed current limit, no trim
Built-in fault protection includes fixed current limiting and over-temperature shutdown. The current limit is non-adjustable, so the 1 A per-channel rating is also the trip threshold — no external sense resistor needed, but no headroom tuning either. The status flag output reports over-current or thermal faults back to the host controller.
Serial interface and input-to-output ratio
Control is via a serial interface, with a 3:4 input-to-output ratio — three control lines manage four independent switch channels. The device does not require a separate Vcc/Vdd supply for its internal logic; it derives bias from the load rails.
Housed in a 30-pin SSOP (0.209" body width, 5.30 mm) surface-mount package.
No official direct replacement or cross-reference is listed by the manufacturer, so the TPS2226 base number is the one to qualify into the BOM.