Autonomous CMOS Power Management Integrated Circuit for Electrostatic Kinetic Energy Harvesters eKEH In this paper we present an autonomous Power Management Integrated Circuit PMIC for an electretbiased electrostatic kinetic energy harvester with a Bennetu0027s doubler conditioning circuit. The circuit is designed in high voltage  0.35 mumathrmm  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 xe2x80x9ccold startxe2x80x9d mechanism and with a xe2x80x9csafe modexe2x80x9d (Recovery) feature that permits to the system to stay active (awake) for a longer time after external vibrations stop temporarily. An ultralow static power hysteresis comparator is designed for a specific control of the capacitive transduceru0027s 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 stateofthe art capacitive harvesting MEMS devices.

Highest Maximum Power Point of Radially Distant Inductively Coupled Power Receivers With Deep Submicron CMOS Inductively coupled power receivers for embedded microsensors are often tiny and distant from their transmitting sources. To sustain microsensors as long as possible, the power receiver should draw power whenever possible and output the highest power possible. Of reported stateoftheart technologies, switched resonant halfbridges require fewer components, are less breakdownlimited, and output as much or more power than the others. This paper derives and shows with measurements the highest possible maximum power point (MPP) for switched resonant halfbridges. The theory predicts the optimal time, duration, and frequency of the energy transfers that charge the battery. Measurements of a 0.18xcexbcm CMOS power receiver demonstrate that the receiver outputs more than 98.7% of the actual MPP at the predicted settings when the coupling factor between the transmitting and the receiving coils is 0.15%xe2x80x931.14%.