*Article* **A Fully Integrated AC-DC Converter in 1 V CMOS for Electrostatic Vibration Energy Transducer with an Open Circuit Voltage of 10 V**

**Yosuke Ishida † and Toru Tanzawa \***

> Graduate School of Integrated Science and Technology, Shizuoka University, Hamamatsu 432-8561, Japan; ishida.yohsuke.15@shizuoka.ac.jp

**\*** Correspondence: toru.tanzawa@shizuoka.ac.jp

† Current address: Anritsu Corp., Atsugi 243-8555, Japan.

**Abstract:** This paper proposes an AC-DC converter for electrostatic vibration energy harvesting. The converter is composed of a CMOS full bridge rectifier and a CMOS shunt regulator. Even with 1 V CMOS, the open circuit voltage of the energy transducer can be as high as 10 V and beyond. Bandgap reference (BGR) inputs a regulated voltage, which is controlled by the output voltage of the BGR. Built-in power-on reset is introduced, which can minimize the silicon area and power to function normally found upon start-up. The AC-DC converter was fabricated with a 65 nm low-Vt 1 V CMOS with 0.081 mm<sup>2</sup> . 1 V regulation was measured successfully at 20–70 ◦C with a power conversion efficiency of 43%.

**Keywords:** AC-DC converter; shunt regulator; full bridge rectifier; electrostatic vibration energy harvesting; fully integrated; IoT
