High efficiency, low-voltage and self-adjusting charge pump with enhanced impedance matching

This paper presents a novel fully integrated charge pump voltage up-converter designed in 0.35 mum standard CMOS process. This proposed charge pump is composed for dynamic input impedance adaptation for optimal loading of micro-energy harvesting generators. The ac generator voltage is oversampled with two flying capacitor arrays. Thus, conversion of alternating input voltages into a dc output-voltage by automatically adapting the conversion ratio is achieved. This yields improved harvesting and conversion efficiency of over 85% in average with a given minimum generator voltage of 330 mV at a nominal generator power of 100 muW.