LTC1149-5 Datasheet | Linear Technology

LTC1149 LTC1149-3.3/LTC1149-5 High Efficiency Synchronous Step-Down Switching Regulators Features s s s DESCRIPTIO s s s s s s s Operation to 48V Input Voltage Ultrahigh Efficiency: Up to 95% Current Mode Operation for Excellent Line and Load Transient Response High Efficiency Maintained over Wide Current Range Logic-Controlled Micropower Shutdown Short-Circuit Protection Very Low Dropout Operation: 100% Duty Cycle Synchronous FET Switching for High Efficiency Adaptive Nonoverlap Gate Drives Available in 16-Pin Narrow SO Package The LTC ®1149 series is a family of synchronous stepdown switching regulator controllers featuring automatic Burst Mode TM operation to maintain high efficiencies at low output currents. These devices drive external plementary power MOSFETs at switching frequencies up to 250k Hz using a constant off-time current-mode architecture. Special onboard regulation and level-shift circuitry allow operation at input voltages from dropout to 48V (60V absolute max). The constant off-time architecture maintains constant ripple current in the inductor, easing the design of wide input range converters. Current mode operation provides excellent line and load transient response. The operating current level is user-programmable via an external current sense resistor. The LTC1149 series incorporates automatic power saving Burst Mode operation when load currents drop below the level required for continuous operation. Standby power is reduced to only about 8m W at VIN = 12V. In shutdown, both MOSFETs are turned off. APPLICATI s s s s s s Notebook and Palmtop puters Portable Instruments Battery-Operated Digital Devices Industrial Power Distribution Avionics Systems Tele Power Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. TYPICAL APPLICATI 1N4148 CAP 0.068µF VIN 1N4148 PGATE PDRIVE 0.047µF D1 1N5819 P-CHANNEL IRFR9024 L- 62µH + CIN 100µF...