Regulator with a low quiescent draw and dual-mode output
The Maxim MAX603ESA+ is a single-output positive LDO regulator that delivers up to 500 mA from an input rail as high as 11.5 V. Its standout feature for always-on or battery-backed rails is the 35 µA quiescent current — that is the current the regulator burns just to stay alive, regardless of load. The output can be set as adjustable from 1.25 V up to 11 V, or strapped for a fixed 5 V output using the same pin configuration. Dropout voltage is 0.55 V at the full 500 mA load, so the input must stay at least that far above the output to maintain regulation. Protection circuits cover over-current, over-temperature, and reverse polarity on the input.
Housed in an 8-pin SOIC package (3.90 mm body width), the MAX603ESA+ is a surface-mount part that reflows on a standard SOIC-8 land pattern.