Energy extraction from piezoelectric transducers is commonly performed with full bridge rectifiers that may be implemented with active diodes in order to increase energy extraction efficiency. In very low voltage applications, the use of voltage doublers is crucial as they provide a larger voltage at the output. In this article, a self starting up, low voltage voltage doubler implemented with active diodes is proposed to extract energy from a remote powered magnetoelectric transducer. The limitations to tackle during the design of active diodes are analyzed in order to maximize the extracted energy from the transducer. With such considerations, two low power active diodes have been designed, consisting in a supply compatible and a ground compatible comparators driving MOS switches. The proposed active diodes provide a low power overhead and < 200 ns delay time. The voltage doubler is capable of achieving an energy extraction efficiency of up to 94.9%, performing optimally at an output voltage of 1.4 V.