DESCRIPTION
The LTC1143 series is a dual step-down switching regulator controller featuring automatic Burst ModeTM operation to maintain high efficiencies at low output currents. This device is composed of two separate regulator blocks, each driving an external power MOSFET at switching frequencies up to 400kHz using a constant off-time current mode architecture. Both fixed and adjustable voltages are available.

FEATURES
■ Dual Outputs
   LTC1143, LTC1143L: 3.3V, 5V
   LTC1143L-ADJ: Dual Adjustable
■ Very High Efficiency: Over 95% Possible
■ Current Mode Operation for Excellent Line and Load
   Transient Response
■ High Efficiency Maintained over Three Decades of
   Output Current
■ Low Standby Current at Light Loads: 160µA/Output
■ Logic-Controlled Shutdown (LTC1143, LTC1143L)
■ Wide VIN Range: 3.5V to 16V
   (LTC1143L, LTC1143L-ADJ)
■ Very Low Dropout Operation: 100% Duty Cycle
■ Available in Narrow 16-Pin SO Package

APPLICATIONS
■ Personal Digital Assistants
■ Notebook and Palmtop Computers
■ Battery-Operated Digital Devices
■ Portable Instruments
■ DC Power Distribution Systems