General Description
The MAX8743 is a dual pulse-width modulation (PWM) controller configured for step-down (buck) topologies that provides the high efficiency, excellent transient response, and high DC output accuracy necessary for stepping down high-voltage batteries to generate lowvoltage chipset and RAM power supplies in notebook computers. The CS_ inputs can be used with low-side sense resistors to provide accurate current limits or can be connected to LX_, using low-side MOSFETs as current-sense elements. High output impedance in shutdown eliminates negative output voltages, saving the cost of a Schottky diode at the output.

Features
♦ Ultra-High Efficiency
♦ Accurate Current-Limit Option
♦ Quick-PWM™ with 100ns Load-Step Response
♦ 1% VOUT Accuracy over Line and Load
♦ High Output Impedance in Shutdown
♦ Dual Mode™ Fixed 1.8V/1.5V/Adj or 2.5V/Adj Outputs
♦ Adjustable 1V to 5.5V Output Range
♦ 2V to 28V Battery Input Range
♦ 200kHz/300kHz/420kHz/540kHz Nominal Switching Frequency
♦ Adjustable Overvoltage Protection
♦ 1.7ms Digital Soft-Start
♦ Drives Large Synchronous-Rectifier FETs
♦ Power-Good Window Comparator
♦ 2V ±1% Reference Output

Applications
    Notebook Computers
    CPU Core Supplies
    Chipset/RAM Supplies as Low as 1V
    1.8V and 2.5V I/O Supplies