LTC1625 Datasheet | Linear Technology

LTC1625 No RSENSETM Current Mode Synchronous Step-Down Switching Regulator Features s s s s s s s s s s s s s s s s DESCRIPTION The LTC®1625 is a synchronous step-down switching regulator controller that drives external N-Channel power MOSFETs using few external ponents. Current mode control with MOSFET VDS sensing eliminates the need for a sense resistor and improves efficiency. The frequency of a nominal 150k Hz internal oscillator can be synchronized to an external clock over a 1.5:1 frequency range. Burst Mode TM operation at low load currents reduces switching losses and low dropout operation extends operating time in battery-powered systems. A forced continuous mode control pin can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded. Fault protection is provided by foldback current limiting and an output overvoltage parator. An external capacitor attached to the RUN/SS pin provides soft start capability for supply sequencing. A wide supply range allows operation from 3.7V (3.9V for LTC1625I) to 36V at the input and 1.19V to VIN at the output. , LTC and LT are registered trademarks of Linear Technology Corporation. No RSENSE and Burst Mode are trademarks of Linear Technology Corporation. Highest Efficiency Current Mode Controller No Sense Resistor Required Stable High Current Operation Dual N-Channel MOSFET Synchronous Drive Wide VIN Range: 3.7V to 36V Wide VOUT Range: 1.19V to VIN ± 1% 1.19V Reference Programmable Fixed Frequency with Injection Lock Very Low Drop Out Operation: 99% Duty Cycle Forced Continuous Mode Control Pin Optional Programmable Soft Start Pin Selectable Output Voltage Foldback Current Limit Output Overvoltage Protection Logic Controlled Micropower Shutdown: IQ < 30µA Available in 16-Lead Narrow SSOP and SO Packages U APPLICATIONS s s s s Notebook and Palmtop puters, PDAs Cellular Telephones and Wireless Modems Battery Chargers Distributed Power TYPICAL APPLICATION Effici...