Single and Dual PCMCIA Protected 3.3V/5V VCC Switches

The LTC1470 switches the VCC pins of a Personal Computer Memory Card International Association (PCMCIA) card slot between three operating states: OFF, 3.3V and 5V. Two low RDS(ON) N-channel power MOSFETs are driven by a built-in charge pump which generates a voltage higher than the supply voltage to fully enhance each switch when selected by the input control logic.

The LTC1470 inputs are compatible with industry standard PCMCIA controllers. A built-in XOR ensures that both switches are never on at the same time. This function also makes the LTC1470 compatible with both active-low and active-high controllers (see Applications Information section). The switch rise times are controlled to eliminate power supply glitching.

The LTC1470 features built-in SafeSlot™ current limit and thermal shutdown. The output is limited to 1A during short circuit to ground but 2A of peak operating current is allowed.

The LTC1471 is a dual version of the LTC1470 and is available in a 16-pin SO package.

Applications

* Notebook Computers

* Palmtop Computers

* Pen-Based Computers

* Handi-Terminals

* PC Card Reader/Writers

* 3.3V/5V Power Supply Switch

* Single 3.3V/5V Switch in 8-Pin SO Package * Dual 3.3V/5V Switch in 16-Pin SO Package * Built-In Current Limit and Thermal Shutdown * Built-In Charge Pumps (No 12V Required) * Extremely Low RDS(ON) MOSFET Switches * Output Current Capability: 1A * Inrush Current Limited (Drives 150µF Loads) * Quiescent Current in Standby: 1µA * No Parasitic Body Diodes * Built-In XOR Function Eliminates “Glue” Logic * Break-Before-Make Switching * Controlled Rise and Fall Times