DESCRIPTION
The LTC®1142/LTC1142L/LTC1142HV are dual synchronous step-down switching regulator controllers featuring automatic Burst ModeTM operation to maintain high efficiencies at low output currents. The devices are composed of two separate regulator blocks, each driving a pair of external complementary power MOSFETs, at switching frequencies up to 250kHz, using a constant off-time current mode architecture providing constant ripple current in the inductor.

FEATURES
■ Dual Outputs: 3.3V and 5V or User Programmable
■ Ultrahigh Efficiency: Over 95% Possible
■ Current Mode Operation for Excellent Line and Load Transient Response
■ High Efficiency Maintained over 3 Decades of Output Current
■ Low Standby Current at Light Loads: 160µA/Output
■ Independent Micropower Shutdown: IQ < 40µA
■ Wide VIN Range: 3.5V to 20V
■ Very Low Dropout Operation: 100% Duty Cycle
■ Synchronous FET Switching for High Efficiency
■ Available in Standard 28-Pin SSOP

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