The MAX1556/MAX1556A/MAX1557 are low-operating-
current (16μA), fixed-frequency step-down regulators.
High efficiency, low-quiescent operating current, low
dropout, and minimal (27μA) quiescent current in
dropout make these converters ideal for powering
portable devices from 1-cell Li-ion or 3-cell alkaline/NiMH
batteries. The MAX1556 delivers up to 1.2A; has pin-
selectable 1.8V, 2.5V, and 3.3V outputs; and is also
adjustable. The MAX1557 delivers up to 600mA; has pin-
selectable 1V, 1.3V, and 1.5V outputs; and is also
adjustable.
The MAX1556/MAX1556A/MAX1557 contain a low-on-
resistance internal MOSFET switch and synchronous
rectifier to maximize efficiency and dropout perfor-
mance while minimizing external component count. A
proprietary topology offers the benefits of a high fixed-
frequency operation while still providing excellent effi-
ciency at both light and full loads. A 1MHz PWM
switching frequency keeps components small. Both
devices also feature an adjustable soft-start to minimize
battery transient loading.
The MAX1556/MAX1556A/MAX1557 are available in a
tiny 10-pin TDFN (3mm x 3mm) package.
Applications
PDAs and Palmtop Computers
Cell Phones and Smart Phones
Digital Cameras and Camcorders
Portable MP3 and DVD Players