Disclosed is an energy mixer having a first active diode coupled between a first input node and an output node, and a second active diode coupled between a second input node and the output node. A first capacitor is coupled between the first input node and a dynamic node, and a second capacitor is coupled between the second input node and a third node. Switching circuitry is configured to selectively couple the dynamic node between a fixed voltage node and the second input node in response to a control signal provided by control circuitry. When an output voltage at the output node is within a first range, the dynamic node is coupled to the fixed voltage node and when the output voltage is within a lower voltage second range, the dynamic node is coupled to the second input node such that first capacitor and second capacitor are coupled in series.