LTC3778 Datasheet | Linear Technology

LTC3778 Wide Operating Range, No RSENSETM Step-Down Controller Features s s s s s s s s s s s s s s s s DESCRIPTIO U APPLICATIO S s s s s s Wide VIN Range: 4V to 36V Sense Resistor Optional True Current Mode Control 2% to 90% Duty Cycle at 200k Hz t ON(MIN) ≤ 100ns Stable with Ceramic COUT Dual N-Channel MOSFET Synchronous Drive Power Good Output Voltage Monitor ±1% 0.6V Reference Adjustable Current Limit Adjustable Switching Frequency Programmable Soft-Start Output Overvoltage Protection Optional Short-Circuit Shutdown Timer Micropower Shutdown: IQ ≤ 30µA Available in a 1mm 20-Lead TSSOP Package The LTC®3778 is a synchronous step-down switching regulator controller for puter memory, automobile and other DC/DC power supplies. The controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor. Operating frequency is selected by an external resistor and is pensated for variations in VIN and VOUT. Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference, and can assist secondary winding regulation when the main output is lightly loaded. SENSE+ and SENSE- pins provide true Kelvin sensing across the optional sense resistor or the sychronous MOSFET. Fault protection is provided by internal foldback current limiting, an output overvoltage parator, optional shortcircuit shutdown timer and input undervoltage lockout. Soft-start capability for supply sequencing is acplished using an external timing capacitor. The regulator current limit level is user programmable. Wide supply range allows operation from 4V to 36V at the input and from 0.6V up to (0.9)VIN at the output. , LTC and LT are registered trademarks of Linear Technology Corporation. No RSENSE is a trademark of Linear Technology Corporation. Notebook and Palmtop puters, PDAs Battery Chargers Distributed Power Systems DDR Memory Power Supply Automobile DC...