A wide-input-range boost converter with three-phase self-start and adaptive zero current detector for photovoltaic energy harvesting

In this paper, a 0.1–4.2V input boost converter with 1.5 μA quiescent current consumption for microscale photovoltaic energy harvesting applications is proposed. The chip integrates a charge-pump-based three-phase self-start circuit that actives the converter with an input voltage of 0.6V. Moreover, the proposed self-start circuit reduces the capacitance area of charge pump by 40 % and the energy loss by 60 % compared to traditional two-phase self-start circuit. After completing self-start, the converter is capable of harvesting energy from an input voltage as low as 100 mV and covering a wide output power range of 5μW-460mW. The on-time of the high-side switch adapts dynamically to the input and output voltages for zero-current switching by adopting an adaptive zero current detector. The proposed chip has been fabricated using 180 nm CMOS technology and occupies an active area of 0.58 mm². According to the measured efficiency at different load current, a peak efficiency of 93.7 % is achieved.