The MAX1920/MAX1921 step-down converters deliver
over 400mA to outputs as low as 1.25V. These converters
use a unique proprietary current-limited control
scheme that achieves over 90% efficiency. These
devices maintain extremely low quiescent supply current
(50μA), and their high 1.2MHz (max) operating frequency
permits small, low-cost external components. This combination
makes the MAX1920/MAX1921 excellent highefficiency
alternatives to linear regulators in spaceconstrained
applications.
Internal synchronous rectification greatly improves efficiency
and eliminates the external Schottky diode
required in conventional step-down converters. Both
devices also include internal digital soft-start to limit
input current upon startup and reduce input capacitor
requirements.
The MAX1920 provides an adjustable output voltage
(1.25V to 4V). The MAX1921 provides factory-preset
output voltages (see the Selector Guide). Both are
available in space-saving 6-pin SOT23 packages. The
MAX1920 is also available in a 6-pin TDFN package.
Applications
Next-Generation Wireless Handsets
PDAs, Palmtops, and Handy-Terminals
Battery-Powered Equipment
CDMA Power Amplifier Supply