The ADP5304 is a high efficient, ultralow quiescent current step-down regulator that draws only 260 nA of quiescent current to regulate the output at no load.The ADP5304 runs from an input voltage range of 2.15 V to 6.50 V, allowing the use of the multiple alkaline, NiMH, and Lithium cells, or the use of a high impedance power source. The output voltage is selectable from 0.8 V to 5.0 V by an external VID resistor to ground. The total solution requires only four tiny external components.The ADP5304 operates in hysteresis mode via connecting the MODE pin to ground. In hysteresis mode, the regulator achieves excellent efficiency at a power of less than 1 mW and provides up to 50 mA of output load. The device enables very efficient power management to achieve the collection of small amounts of energy from the high impedance battery or the energy harvester to charge up the conventional capacitor or super capacitor.The ADP5304 integrates an ultralow power comparator with a factory programmable voltage reference to monitor the voltage of the input power source. The voltage reference, with hysteresis, is the threshold for the stopping and starting of switching, allowing the use of the high impedance power source.Other key features of the ADP5304 include separate enabling and an output discharge function (QOD). Safety features, such as overcurrent protection, thermal shutdown (TSD), and input undervoltage (UVLO), are also included.The ADP5304 is available in 10-lead, 3 mm × 3 mm LFCSP package rated for the −40°C to +125°C junction temperature range.ApplicationsEnergy (gas, water) meteringEnergy harvesting applicationsPortable and battery-powered equipmentMedical applicationsKeep-alive power supply