DESCRIPTION
The LTC®3718 is a high current, high efficiency synchronous switching regulator controller for DDR and QDRTM memory termination. It operates from an input as low as 1.5V and provides a regulated output voltage equal to (0.5)VIN. The controller uses a valley current control architecture to enable high frequency operation with very low on-times without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN and VOUT. The LTC3718 uses a pair of standard 5V logic level N-channel external MOSFETs, eliminating the need for expensive P-channel or low threshold devices.

FEATURES
■ Very Low VIN(MIN): 1.5V
■ Ultrafast Transient Response
■ True Current Mode Control
■ 5V Drive for N-Channel MOSFETs Eliminates Auxillary 5V Supply
■ No Sense Resistor Required
■ Uses Standard 5V Logic-Level N-Channel MOSFETs
■ VOUT(MIN): 0.4V
■ VOUT Tracks 1/2 VIN or External VREF
■ Symmetrical Source and Sink Output Current Limit
■ Adjustable Switching Frequency
■ tON(MIN) <100ns
■ Power Good Output Voltage Monitor
■ Programmable Soft-Start
■ Output Overvoltage Protection
■ Optional Short-Circuit Shutdown Timer
■ Small 24-Lead SSOP Package

APPLICATIONS
■ Bus Termination: DDR/QDR Memory, SSTL, HSTL, ...
■ Servers, RAID Systems
■ Distributed Power Systems
■ Synchronous Buck with General Purpose Boost