The MAX1602 DC power-switching IC contains a network of low-resistance MOSFET switches that deliver selectable V_CC and V_PP voltages to a single CardBus or PC Card host socket. Key features include low-resistance 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 V_CC switches are static. Power consumption is automatically reduced to 11µA 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 lock-outs. The CMOS/TTL-logic interface is flexible, and can tolerate logic input levels in excess of the positive supply rail.

The MAX1602 fits a complete CardBus/PCMCIA switch into a space-saving, 16-pin QSOP package.