The MAX1602 DC power-switching IC contains a network of low-resistance MOSFET switches that deliver selectable VCC and VPP voltages to a single CardBus or PC Card host socket. Key features include lowresistance switches, small packaging, soft-switching action, and compliance with PCMCIA specifications for 3V/5V switching. 3.3V-only power switching for fast, 32-bit CardBus applications is supported in two ways: low-resistance 3.3V switches allow high 3.3V load currents (up to 1A); and completely independent internal charge pumps let the 3.3V switch operate normally, even if the +5V and +12V supplies are disconnected or turned off to conserve power. The internal charge pumps are regulating types that draw reduced input current when the VCC switches are static. Power consumption is automatically reduced to 11A max when the outputs are high-Z or GND. Other key features include guaranteed specifications for output current limit level, and guaranteed specifications for output rise/fall times (in compliance with PCMCIA specifications). Reliability is enhanced by thermal-overload protection, accurate current limiting, an overcurrent-fault flag output, and undervoltage lockouts. The CMOS/TTL-logic interface is flexible, and can tolerate logic input levels in excess of the positive supply rail.