LTC3736

U U LTC3736 Dual 2-Phase, No RSENSETM, Synchronous Controller with Output Tracking FEATURES ■ No Current Sense Resistors Required ■ Out-of-Phase Controllers Reduce Required Input Capacitance ■ Tracking Function ■ Wide VIN Range: 2.75V to 9.8V ■ Constant Frequency Current Mode Operation ■ 0.6V ±1.5% Voltage Reference ■ Low Dropout Operation: 100% Duty Cycle ■ True PLL for Frequency Locking or Adjustment ■ Selectable Burst Mode®/Forced Continuous Operation ■ Auxiliary Winding Regulation ■ Internal Soft-Start Circuitry ■ Power Good Output Voltage Monitor ■ Output Overvoltage Protection ■ Micropower Shutdown: IQ = 9µA ■ Tiny Low Profile (4mm × 4mm) QFN and Narrow SSOP Packages U APPLICATIO S ■ One or Two Lithium-Ion Powered Devices ■ Notebook and Palmtop Computers, PDAs ■ Portable Instruments ■ Distributed DC Power Systems DESCRIPTIO The LTC®3736 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. Burst Mode 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 can be programmed u...