An energy harvesting circuit receives an input voltage from a transducer and uses a single inductor operating in a DC-DC converter charging mode to generate charging current at a first output coupled to an energy storage device where a supply voltage is stored. The energy harvesting circuit further receives the supply voltage from the energy storage device and uses the same single inductor operating in a DC-DC converter regulating mode to generate load current at a second output where a regulated load voltage is provided. The energy harvesting circuit switches between the charging mode and the regulating mode in accordance with a discontinuous mode (DCM) control process.