LTC3717EGN#TR

Product Summary

The LTC3717EGN#TR 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. Forced continuous operation reduces noise and RF interference. Output voltage of the LTC3717EGN#TR is internally set to half of VREF, which is user programmable. The applications of the LTC3717EGN#TR are (1)bus termination: DDR and QDR memory, SSTL, HSTL; (2)notebook computers, desktop servers; (3)tracking power supply.

Parametrics

LTC3717EGN#TR absolute maximum ratings: (1)Input Supply Voltage (VCC, ION): 36V to –0.3V; (2)Boosted Topside Driver Supply Voltage (BOOST): 42V to –0.3V; (3)SW Voltage: 36V to –5V; (4)EXTVCC, (BOOST – SW), RUN/SS, PGOOD Voltages: 7V to –0.3V; (5)VREF, VRNG Voltages: (INTVCC + 0.3V)to –0.3V; (6)ITH, VFB Voltages: 2.7V to –0.3V; (7)TG, BG, INTVCC, EXTVCC Peak Currents: 2A; (8)TG, BG, INTVCC, EXTVCC RMS Currents: 50mA; (9)Operating Ambient Temperature Range: –40°C to 85°C; (10)Junction Temperature: 125°C; (11)Storage Temperature Range: –65°C to 150°C; (12)Lead Temperature (Soldering, 10 sec): 300°C.

Features

LTC3717EGN#TR features: (1)VOUT = 1/2 VIN (Supply Splitter); (2)Adjustable and Symmetrical Sink/Source Current Limit up to 20A; (3)±0.65% Output Voltage Accuracy; (4)Up to 97% Efficiency; (5)No Sense Resistor Required; (6)Ultrafast Transient Response; (7)True Current Mode Control; (8)2% to 90% Duty Cycle at 200kHz; (9)tON(MIN)£ 100ns; (10)Stable with Ceramic COUT; (11)Dual N-Channel MOSFET Synchronous Drive; (12)Power Good Output Voltage Monitor; (13)Wide VCC Range: 4V to 36V; (14)Adjustable Switching Frequency up to 1.5MHz; (15)Output Overvoltage Protection; (16)Optional Short-Circuit ShutdowTimer; (17)Available ia 16-PiNarrow SSOP Package.

Diagrams