The TPS2231PWPR is a Texas Instruments ExpressCard™ power switch that routes 1.5 V and 3.3 V to the card slot through three high-side outputs, each rated 1.3 A continuous. The 45 mOhm typical on-resistance sets the conduction loss at about 60 mW per channel at 1.3 A — low enough that the 24-HTSSOP exposed pad handles the thermal load without forced airflow in a typical telecom line card or industrial controller.
1.3 A per output — load margin for simultaneous ExpressCard rails
Each of the three outputs delivers 1.3 A maximum. In a standard ExpressCard application the 3.3 V rail draws roughly 0.9 A and the 1.5 V rail draws about 0.6 A, leaving 400 mA and 700 mA of headroom respectively. That margin absorbs inrush from hot-plug insertion without tripping the fixed current limit. The switch does not require a Vcc/Vdd bias supply — it powers itself from the load rails, which simplifies the BOM by eliminating a separate gate-drive regulator.
Fault protection and status flags
Built-in fault protection includes fixed current limiting and over-temperature shutdown. The Power Good and Status Flag outputs let a system controller or FPGA monitor the rail health and sequence downstream loads — a common requirement in ExpressCard host controllers and PCIe-based add-in card designs.