DESCRIPTION
The LTC®3717 is a synchronous step-down switching regulator controller for double data rate (DDR) and Quad Data RateTM (QDRTM) memory termination. 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 compensated for variations in VIN.

FEATURES
■ VOUT = 1/2 VIN (Supply Splitter)
■ Adjustable and Symmetrical Sink/Source Current Limit up to 20A
■ ±0.65% Output Voltage Accuracy
■ Up to 97% Efficiency
■ No Sense Resistor Required
■ Ultrafast Transient Response
■ True Current Mode Control
■ 2% to 90% Duty Cycle at 200kHz
■ tON(MIN) ≤ 100ns
■ Stable with Ceramic COUT
■ Dual N-Channel MOSFET Synchronous Drive
■ Power Good Output Voltage Monitor
■ Wide VCC Range: 4V to 36V
■ Adjustable Switching Frequency up to 1.5MHz
■ Output Overvoltage Protection
■ Optional Short-Circuit Shutdown Timer
■ Available in a 16-Pin Narrow SSOP Package

APPLICATIONS
■ Bus Termination: DDR and QDR Memory, SSTL, HSTL, ...
■ Notebook Computers, Desktop Servers
■ Tracking Power Supply