A wide input range, 94% peak efficiency auto‐select multi‐mode boost converter for thermoelectric energy harvesting

Abstract

SummaryIn this paper, a high‐efficiency DC–DC boost converter is proposed for thermal energy harvesting systems. The converter's efficiency is improved using a low‐power digital operating mode detector circuit. The operating mode detector circuit changes the converter's operating mode between the continuous conduction mode (CCM) and discontinuous conduction mode (DCM) at a specific input voltage (boundary input voltage), which reduces the total losses, thus improves the efficiency and increases the input voltage range. Besides, the proper boundary input voltage is calculated as a function of the boost converter's parameters. Finally, the proposed converter is designed in a standard 0.18 μm CMOS process. Simulation results show that the peak efficiency of the converter can be up to 94%, 60.4%, and 35% at 300, 20, and 15 mV of the open‐circuit voltage, respectively.