The ADP2102 is a low quiescent current step-down DC-DC converter optimized to regulate low output voltages in a compact 3mmx3mm LFCSP package. At high load currents, the ADP2102 uses a current mode, constant on time, pseudo fixed frequency, valley current control scheme for excellent stability and transient response with very few, small external components. To ensure the longest battery life in portable applications, the ADP2102 has a power saving mode that reduces the switching frequency under light load conditions to significantly reduce the quiescent current. The ADP2102 runs from input voltages from 2.7V to 5.5V allowing single Li+/Li- polymer cell, multiple Alkaline/Ni-MH cells and other standard power sources. ADP2102 output voltage is adjustable from 0.8V to 1.875V, while the suffix part numbers ADP2102-XX indicate pre-set voltage ranges of 1.875, 1.8, 1.5, 1.375, 1.25, 1.2, 1.0 & 0.8V. All versions include an internal power switch and a synchronous rectifier for high efficiency while internal compensation guarantees minimal number of external components. During logic-controlled shutdown, the input is disconnected from the output and it draws less than 0.1A from the input source. Other key features include under voltage lockout to prevent deep battery discharge and soft start to prevent input current overshoot at startup.