LTC1142L Datasheet | Linear Technology

Features s Dual Outputs: 3.3V and 5V or User Programmable s Ultrahigh Efficiency: Over 95% Possible s Current Mode Operation for Excellent Line and Load Transient Response s High Efficiency Maintained over 3 Decades of Output Current s Low Standby Current at Light Loads: 160µA/Output s Independent Micropower Shutdown: IQ < 40µA s Wide VIN Range: 3.5V to 20V s Very Low Dropout Operation: 100% Duty Cycle s Synchronous FET Switching for High Efficiency s Available in Standard 28-Pin SSOP U APPLICATIO S s Notebook and Palmtop puters s Battery-Operated Digital Devices s Portable Instruments s DC Power Distribution Systems LTC1142/LTC1142L/LTC1142HV Dual High Efficiency Synchronous Step-Down Switching Regulators DESCRIPTIO The LTC®1142/LTC1142L/LTC1142HV are dual synchronous step-down switching regulator controllers featuring automatic Burst Mode TM operation to maintain high efficiencies at low output currents. The devices are posed of two separate regulator blocks, each driving a pair of external plementary power MOSFETs, at switching frequencies up to 250k Hz, using a constant off-time current mode architecture providing constant ripple current in the inductor. The operating current level for both regulators is user programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V- to 18V (20V maximum). Constant off-time architecture provides low dropout regulation limited only by the RDS(ON) of the external MOSFET and resistance of the inductor and current sense resistor. The LTC1142 series is ideal for applications requiring dual output voltages with high conversion efficiencies over a wide load current range in a small amount of board space. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. TYPICAL APPLICATIO VIN 5.2V TO 18V VOUT3 3.3V/2A RSENSE3 0.05Ω + CIN3 22µF 25V ×2 L1 50µH 0.22µF P-CH Si9430DY 24 VIN3 23 PDRIVE 3 0V =...