DESCRIPTION
The LTC®1147 series are step-down switching regulator controllers featuring automatic Burst ModeTM operation to maintain high efficiencies at low output currents. These devices drive an external P-channel power MOSFET at switching frequencies exceeding 400kHz using a constant off-time current mode architecture providing constant ripple current in the inductor.

■ Very High Efficiency: Over 95% Possible
■ Wide VIN Range: 3.5V* to 16V
■ Current Mode Operation for Excellent Line and Load Transient Response
■ High Efficiency Maintained Over Three Decades of Output Current
■ Low 160µA Standby Current at Light Loads
■ Logic Controlled Micropower Shutdown: IQ < 20µA
■ Short-Circuit Protection
■ Very Low Dropout Operation: 100% Duty Cycle
■ High Efficiency in a Small Amount of Board Space
■ Output Can Be Externally Held High in Shutdown
■ Available in 8-Pin SO Package FEATURES

APPLICATIONS
■ Notebook and Palmtop Computers
■ Portable Instruments
■ Battery-Operated Digital Devices
■ Cellular Telephones
■ DC Power Distribution Systems
■ GPS Systems