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In this paper we present an autonomous Power Management Integrated Circuit PMIC for an electret-biased electrostatic kinetic energy harvester with a Bennet's doubler conditioning circuit. The circuit is designed in high voltage 0.35 μm standard bulk CMOS technology. It supplies a low voltage load from the energy extracted from a high voltage transducer. The circuit is provided with a "cold start" mechanism and with a "safe mode" (Recovery) feature that permits to the system to stay active (awake) for a longer time after external vibrations stop temporarily. An ultra-low static power hysteresis comparator is designed for a specific control of the capacitive transducer's conditioning circuit. The autonomy of the system is ensured by a voltage regulator that supplies the internal blocks of the circuit with 1.1 V. The proposed design consumes less than 400 nW making it adequate for use with existing stateof-the art capacitive harvesting MEMS devices.

This article presents a universal implementation of a Maximum Power Point Tracking solution for a kinetic energy harvester composed of an electrostatic transducer in association with a capacitive charge pump. The proposed MPPT solution, based on "perturb and observe" method, selects automatically and in real time the optimal electrical state of the charge pump (the voltage of the reservoir capacitor), so to guarantee the maximum of the extracted power under current operation conditions. The proposed solution is implemented alongside a Power Management Integrated Circuit (PMIC) which offers a possibility to control the reservoir's voltage.