An comparator based active rectifier for vibration energy harvesting systems

Harvesting ambient vibration energy through PE means is a popular energy harvesting technique. The main limitation of this harvesting system is in their interface circuitry. In this paper, a highly efficient active switch-only rectifier is proposed. By replacing the conventional full bridge rectifier with the cross-coupled active one in the passive switch-only rectifier, together with simple and effective control circuits, the proposed rectifier shows both good power extraction and power conversion capability. Based on 0.18 um CMOS technology, the simulated power efficiency of the proposed rectifier is 91%, and the output power is 144 uW with a 1 uF capacitor and a 95 kΩ load. The proposed active switch-only rectifier improves upon the extractable power and efficiency by 1.9 times and 1.5 times, respectively, compared to the conventional one; and improves upon the efficiency by 1.5 times compared with passive switch-only rectifier.