General Description
The MAX1626/MAX1627 step-down DC-DC switching controllers provide high efficiency over loads ranging from 1mA to more than 2A. A unique current-limited, pulse-frequency-modulated (PFM) control scheme operates with up to a 100% duty cycle, resulting in very low dropout voltages. This control scheme eliminates minimum load requirements and reduces the supply current under light loads to 90µA (versus 2mA to 10mA for common pulse-width modulation controllers).

FEATUREs
♦ Low Dropout Voltage
♦ 100% Maximum Duty Cycle
♦ Soft-Start Limits Start-Up Current
♦ Efficiency >90% (3mA to 2A Loads)
♦ Output Power >12.5W
♦ 90µA Max Quiescent Current
♦ 1µA Max Shutdown Current
♦ Up to 300kHz Switching Frequency
♦ 16.5V Max Input Voltage
♦ Output Voltage: 5V/3.3V (MAX1626)
                             Adjustable (MAX1627)
♦ Current-Limited Control Scheme

APPLICATIONs
   PCMCIA Power Supplies
   Personal Digital Assistants
   Hand-Held Computers
   Portable Terminals
   Low-Cost Notebook Computer Supplies
   5V to 3.3V Green PC Applications
   High-Efficiency Step-Down Regulation
   Minimum-Component DC-DC Converters
   Battery-Powered Applications