Power Efficient Charge Pump with Dynamic Threshold for Implantable Biomedical Transducers

Implantable biomedical transducers generate ultralow voltages which need to be boosted for further usage in energy harvesting. This paper presents a power efficient charge pump with dynamic threshold realized using tree topology to boost such ultralow voltages. The proposed charge pump has shown a better performance over other converters in terms of power efficiency and output current for such ultralow voltage applications. The performance has been validated through mathematical analysis and simulations. Three voltages, 130mV, 140mV and 150 mV have been boosted to 0.5 V to measure the performance of proposed charge pump. The voltage source has been realized using photovoltaic (PV) cell. The simulations have been carried out with LTspice in 0.18µm CMOS technology using TSMC model.