The ADP2119/ADP2120 are low quiescent current， synchronous， step-down dc-to-dc regulators in a compact 3 mm × 3 mm LFCSP_WD package. Both devices use a current mode， constant frequency pulse-width modulation （PWM） control scheme for excellent stability and transient response. Under light load conditions， they can be configured to operate in a pulse frequency modulation （PFM） mode， which reduces switching frequency to save power. The ADP2119/ADP2120 support input voltages from 2.3 V to 5.5 V. The output voltage can be adjusted from 0.6 V up to the input voltage （VIN） for the adjustable version， whereas the fixed output version is available in preset output voltage options of 3.3 V， 2.5 V， 1.8 V， 1.5 V， 1.2 V， and 1.0 V. The ADP2119/ADP2120 require minimal external parts and provide a high efficiency solution with their integrated power switches， synchronous rectifiers， and internal compensation. Each IC draws less than 2 μA current from the input source when it is disabled. Other key features include undervoltage lockout （UVLO）， integrated soft start to limit inrush current at startup， overvoltage protection （OVP）， overcurrent protection