*Article* **A Dynamic Threshold Cancellation Technique for a High-Power Conversion Efficiency CMOS Rectifier**

**António Godinho 1,†, Zhaochu Yang 1,†, Tao Dong 2,\*, Luís Gonçalves 3, Paulo Mendes 3, Yumei Wen 4, Ping Li 4 and Zhuangde Jiang 1**


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> † Authors whom first authorship is shared by António Godinho and Zhaochu Yang.

**Abstract:** Power conversion efficiency (PCE) has been one of the key concerns for power managemen<sup>t</sup> circuits (PMC) due to the low output power of the vibrational energy harvesters. This work reports a dynamic threshold cancellation technique for a high-power conversion efficiency CMOS rectifier. The proposed rectifier consists of two stages, one passive stage with a negative voltage converter, and another stage with an active diode controlled by a threshold cancellation circuit. The former stage conducts the signal full-wave rectification with a voltage drop of 1 mV, whereas the latter reduces the reverse leakage current, consequently enhancing the output power delivered to the ohmic load. As a result, the rectifier can achieve a voltage and power conversion efficiency of over 99% and 90%, respectively, for an input voltage of 0.45 V and for low ohmic loads. The proposed circuit is designed in a standard 130 nm CMOS process and works for an operating frequency range from 800 Hz to 51.2 kHz, which is promising for practical applications.

**Keywords:** vibration energy harvester; power managemen<sup>t</sup> circuit; CMOS rectifier; dynamic threshold cancellation technique; high power conversion efficiency
