Design of Switched-Capacitor Voltage Boost Converter for Low-Voltage and Low-Power Energy Harvesting Systems

Abstract

This paper discusses and elaborates an analytical model of a multi-stage switched-capacitor (SC) voltage boost converter (VBC) for low-voltage and low-power energy harvesting systems, because the output impedance of the VBC, which is derived from the analytical model, plays an important role in the VBC's performance. In our proposed method, we focus on currents flowing into input and output terminals of each stage and model the VBCs using switching frequency f , charge transfer capacitance C F , load capacitance C L , and process dependent parasitic capacitance's parameter k. A comparison between simulated and calculated results showed that our model can estimate the output impedance of the VBC accurately. Our model is useful for comparing the relative merits of different types of multi-stage SC VBCs. Moreover, we demonstrate the performance of a prototype SC VBC and energy harvesting system using the SC VBC to show the effectiveness and feasibility of our proposed design guideline.

Fully-integrated switched-capacitor voltage boost converter with digital maximum power point tracking for low-voltage energy harvesting

“…This was because our proposed MPPT control circuit was able to generate an appropriate frequency for the SC VBC. The ripple of the output power increased slightly because the output impedance of the converter was reduced by increasing the frequency 26) and the output current increased. Figure 22 shows the measured voltage conversion ratio (VCR) of the proposed circuit.…”

“…As each stage as V H and V L . 26) We choose the topology shown in Fig. 4 because it has the smallest output impedance.…”

“…The MPPT control maximizes the output power of the PV cell. As discussed in previous research, 26) the impedance Z SC of the SC VBC is expressed as…”

Ultra-low power low-dropout linear regulator with a load current tracking bias current generator for loT devices

“…[1][2][3][4][5][6][7][8][9][10][11] Energy harvesting has attracted attention as an alternative power source of batteries. [12][13][14][15][16][17][18][19][20][21][22][23][24] However, the output voltage and power of small energy harvesters are basically weak and easily lost, while the operating voltage of IoT devices will be 1.2 V or higher and the current consumption in IoT devices will be in the ranges from several nA to several hundred μA. 2) Thus, a power management system (PMS) is necessary for stable and sustainable operation.…”

Switched-capacitor voltage buck converter with variable step-down and switching frequency controllers for low-power and high-efficiency IoT devices

“…Energy harvesting and power management techniques have been developed towards battery-and maintenance-free autonomous IoT (Internet-of-Things) devices. [1][2][3][4][5][6][7][8][9][10][11][12][13] Intermittent power management systems, shown in Fig. 1, are widely used to operate application circuits and systems stably because the output voltages of small energy harvesters are usually low and easily lost.…”