LTC3717-1

` V<sub>OUT</sub> = 1/2 V<sub>REF</sub>
` Adjustable and Symmetrical Sink/Source Current Limit up to 20A
` True Current Mode Control with Optional Use of Sense Resistor
` V_ON and ION Pins Allow Constant Frequency Operation During Input and Output Voltage Changes
` ±0.65% Output Voltage Accuracy
` Up to 97% Efficiency
` Ultrafast Transient Response
` 2% to 90% Duty Cycle at 200kHz
` t<sub>ON(MIN)</sub> 100ns
` Stable with Ceramic COUT
` Power Good Output Voltage Monitor
` Wide VIN Range: 4V to 36V
` Adjustable Switching Frequency up to 1.5MHz
` Output Overvoltage Protection
` Optional Short-Circuit Shutdown Timer
` Available in a 5mm ´ 5mm QFN Package

Boosted Topside Driver Supply Voltage
(BOOST) .................................................. 42V to 0.3V
V_IN, I_ON, SW, SENSE+ Voltage ................ 36V to 0.3V
EXTVCC, DRVCC, RUN/SS, PGOOD,
(BOOST SW) Voltages .......................... 7V to 0.3V
VON, VREF, VRNG Voltages ...(INTV_CC + 0.3V) to 0.3V
ITH, VFB Voltages................................... 2.7V to 0.3V
TG, BG, INTV_CC, EXTV_CC, DRV_CC Peak Currents ....... 2A
TG, BG, INTV_CC, EXTV_CC, DRV_CC RMS Currents .. 50mA
Operating Ambient Temperature
Range (Note 4) ................................... 40°C to 85°C
Junction Temperature (Note 2) ........................... 125°C
Storage Temperature Range ............. 65°C to 125°C
Reflow Peak Body Temperature .......................... 260°C

The LTC^®3717-1 is a synchronous step-down switching regulator controller for double data rate (DDR) and Quad Data RateTM (QDRTM) memory termination. The controller of LTC3717-1 uses a valley current control architecture to deliver very low duty cycles with or without a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in V_IN and V_OUT.

Forced continuous operation reduces noise and RF interference. Output voltage is internally set to half of V_REF, which is user programmable.

Fault protection is provided by an output overvoltagecomparator and optional short-circuit shutdown timer. Soft-start capability for supply sequencing is accomplishedusing an external timing capacitor. The regulatorcurrent limit level of LTC3717-1 is symmetrical and user programmable.Wide supply range allows operation from 4V to 36V at the V_CC input.