Protected PCMCIA VCC and VPP Switching Matrix

The LTC1472 switching matrix routes power to both the VCC and VPP power supply pins of the PCMCIA compatible card socket. The VCC output of the LTC1472 is switched between three operating states: OFF, 3.3V, and 5V. The VPP output is switched between four operating states: 0V, VCC, 12V, and Hi-Z. The output voltages are selected by two sets of digital inputs which are compatible with industry standard PC Card controllers (see Truth Tables).

The Vcc output of the LTC1472 can supply up to 1A of current and the VPP output up to 120mA. Both switches have built-in SafeSlot™ current limiting and thermal shutdown to protect the card, socket and power supply against accidental short-circuit conditions.

The LTC1472 is designed to conserve power by automatically dropping to 1µA standby current when the two outputs are switched OFF. A shutdown pin is provided which holds the external 12V regulator in standby mode except when required for VPP power.

The LTC1472 is available in 16-pin SO.

Applications

* Notebook Computers

* Palmtop Computers

* Pen-Based Computers

* Handi-Terminals

* Bar-Code Readers

* Both VCC and VPP Switching in a Single Package

* Built-In Current Limit and Thermal Shutdown

* 16-Pin (Narrow) SOIC Package

* Inrush Current Limited (Drives 150µF Loads)

* Continuous 12V Power Not Required

* Extremely Low RDS(ON) NMOS Switches

* Guaranteed 1A VCC Current and 120mA VPP Current

* 1µA Quiescent Current in Standby

* No External Components Required

* Compatible with Industry Standard Controllers

* Break-Before-Make Switching

* Controlled Rise and Fall Times