MAXIM MAX1626ESA+

The MAX1626/MAX1627 step-down DC-DC controllers operate over a 2.6V to 16.5V input voltage range. The controllers deliver load current from 1mA to more than 2A. The MAX1626 has pin-selectable 3.3V and 5V outputs. The MAX1627 supports adjustable outputs from 1.3V to 16V. A unique current-limited, pulse-frequency-modulation (PFM) control scheme operates up to 100% duty cycle, resulting in very low dropout voltage. This control scheme eliminates minimum load requirements and reduces supply current under light loads to 90μA (versus 2mA to 10mA for common pulse-width modulation controllers). The devices are available in a 8-pin SOIC package (-40°C to +85°C ) and dice [0°C to +70°C]. The MAX1626/MAX1627 are step-down DC-DC controllers designed primarily for use in portable computers and battery-powered devices. Using an external MOSFET and current-sense resistor allows design flexibility and the improved efficiencies associated with high-performance P-channel MOSFETs. A unique, current-limited, pulse-frequency-modulated (PFM) control scheme gives these devices excellent efficiency over load ranges up to three decades, while drawing around 90μA under no load. This wide dynamic range optimizes the MAX1626/MAX1627 for battery-powered applications, where load currents can vary considerably as individual circuit blocks are turned on and off to conserve energy. Operation to a 100% duty cycle allows the lowest possible dropout voltage, extending battery life. High switching frequencies and a simple circuit topology minimize PC board area and component costs.

• Reduce External Components and Total Cost
• 300KHz PWM Switching Reduces Component Size
• Tiny Surface-Mount Inductor
• Reduce Power Dissipation

• 90% Efficiency from 3mA to 2A Loads

• Low Dropout Voltage
• 100% Maximum Duty Cycle
• Reduce Number of DC-DC Controllers to Stock
• Wide 2.6V to 16.5V Input Voltage Options
• Selectable 3.3V and 5V or Adjustable 1.3V to 16V Output Voltage Options
• Reduce System Power Consumption
• 90μA Max Quiescent Current
• 1μA Max Shutdown Current
• Operates Reliably in Adverse Environment
• Soft-Start Limits Startup Current
• Current-Limited Control Scheme
• Increase Design Flexibility
• External P-Channel MOSFET Allows Output Power of >12.5W

• 5V to 3.3V Green PC Applications
• Battery-Powered Applications
• Handheld Computers
• High-Efficiency Step-Down Regulation
• Low-Cost Notebook Computer Supplies
• Minimum Component DC-DC Converters
• PCMCIA Power Supplies
• PDAs and Other Handheld Devices
• Portable Terminals