LTC3736-2

FEATURES n No Current Sense Resistors Required n Out-of-Phase Controllers Reduce Required Input Capacitance n Tracking Function n Wide VIN Range: 2.75V to 9.8V n 0.6V ±1% Voltage Reference n High Current Limit n Constant-Frequency Current Mode Operation n Low Dropout Operation: 100% Duty Cycle n True PLL for Frequency Locking or Adjustment n Selectable Pulse-Skipping/Forced Continuous Operation n Auxiliary Winding Regulation n Internal Soft-Start Circuitry n Power Good Output Voltage Monitor n Output Overvoltage Protection n Micropower Shutdown: IQ = 9μA n Tiny Low Profile (4mm × 4mm) QFN and Narrow SSOP Packages APPLICATIONS n One or Two Lithium-Ion Powered Devices n Notebook and Palmtop Computers, PDAs n Portable Instruments n Distributed DC Power Systems LTC3736-2 Dual 2-Phase, No RSENSETM, Synchronous Controller with Output Tracking DESCRIPTION The LTC®3736-2 is a 2-phase dual synchronous step-down switching regulator controller with tracking that drives external complementary power MOSFETs using few external components. The constant-frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase. Pulse-skipping operation provides high efficiency at light loads. 100% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems. The switching frequency...