MAX651 Datasheet | Maxim Integrated

Description The MAX649/MAX651/MAX652 Bi CMOS, step-down DCDC switching controllers provide high efficiency over three decades of load current. A unique, current-limited pulse-frequency-modulated (PFM) control scheme gives these devices the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using only 100µA of supply current (vs. 2m A to 10m A for PWM converters). The result is high efficiency over loads ranging from 10m A to more than 2.5A. These devices use miniature external ponents. Their high switching frequency (up to 300k Hz) allows for less than 9mm diameter surface-mount inductors. The MAX649/MAX651/MAX652 have dropout voltages less than 1V and accept input voltages up to 16.5V. Output voltages are preset at 5V (MAX649), 3.3V (MAX651), and 3V (MAX652). These controllers can also be adjusted to any voltage from 1.5V to the input voltage by using two resistors. These step-down controllers drive external P-channel MOSFETs at loads greater than 10W. If less power is required, use the MAX639/MAX640/MAX653 step-down converters with on-chip FETs, which allow up to a 225m A load current. ____________________________Features o o o o o o o More than 90% Efficiency (10m A to 1.5A Loads) More than 12.5W Output Power 100µA Max Quiescent Supply Current 5µA Max Shutdown Supply Current Less than 1.0V Dropout Voltage 16.5V Max Input Voltage 5V (MAX649), 3.3V (MAX651), 3V (MAX652), or Adjustable Output Voltage o Current-Limited Control Scheme o Up to 300k Hz Switching Frequency MAX649/MAX651/MAX652 ______________Ordering Information PART MAX649CPA MAX649CSA MAX649C/D MAX649EPA MAX649ESA MAX649MJA TEMP. RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C PIN-PACKAGE 8 Plastic DIP 8 SO Dice- 8 Plastic DIP 8 SO 8 CERDIP- - ________________________Applications 5V-to-3.3V Green PC Applications High-Efficiency Step-Down Regulation Minimum-ponent DC-DC Converters Battery-Powered Applications Ordering...