特点
PolyPhase
TM
Valley Current Mode Controller
Synchronizable to an External Clock with PLL
Coincident or Ratiometric Tracking
Sense Resistor Optional
2% to 90% Duty Cycle at 200kHz
t
ON(MIN)
< 100ns
True Remote Sensing Differential Amplifier
High Efficiency at Both Light and Heavy Loads
Power Good Output Voltage Monitor
0.6V ±1% Reference
Adjustable Current Limit
Programmable Soft-Start and Operating Frequency
Output Overvoltage Protection
Optional Short-Circuit Shutdown Timer
32-Lead (5mm × 5mm) QFN Package
典型应用
典型应用
描述
The LTC ? 3709 is a single output, dual phase, synchronous step-down switching regulator. The controller uses a constant on-time, 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 input supply voltage. An internal phase-locked loop allows the LTC3709 to be synchronized to an external clock.
A TRACK pin is provided for tracking or sequencing the output voltage among several LTC3709 chips or an LTC3709 and other DC/DC regulators. Soft-start is accomplished using an external timing capacitor.
Fault protection is provided by an output overvoltage comparator and an optional short-circuit shutdown timer. The current limit level is user programmable. A wide supply range allows voltages as high as 31V to step down to 0.6V.
Protected by U.S. Patents, including 5481178, 6476589, 6144194, 5847554, 6177678, 6304066, 6580258, 6674274, 6462525, 6593724.
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