PCMCIA power distribution — 4 channels, serial control, 95 mOhm
The Texas Instruments TPS2223ADBG4 is a PCMCIA power switch IC that manages up to four independent output channels from three serial-interface control lines. It is designed for PCMCIA and CardBus slots where the host controller sequences VCC and VPP to the card — the 3:4 input-to-output ratio means three serial bits control four outputs, one of which is typically the VPP programming voltage. Each output is rated for 1 A continuous with a typical on-resistance of 95 mOhm.
Fault protection and status reporting
Built-in fault protection includes fixed current limiting and overtemperature shutdown — no external sense resistor or comparator needed. The status flag output (open-drain, active low) asserts when a fault condition is detected, giving the host controller a direct interrupt signal. The output configuration is high-side, meaning the switch sits between the supply rail and the load. Because the device does not require a Vcc/Vdd bias supply — the gate drive is derived from the load voltage itself — it simplifies the power tree for space-constrained PCMCIA implementations.
The 24-SSOP package (5.30 mm body width, 0.209-inch pitch) is a surface-mount footprint compatible with standard reflow profiles.