A 190 mV start-up and 59.2% efficiency CMOS gate boosting voltage doubler charge pump in 0.18 urn standard CMOS process for energy harvesting

摘要

A start-up charge pump circuit for an extremely low input voltage (V-IN) is proposed and demonstrated. The proposed circuit uses an inverter level shifter to generate a 2V(IN) voltage swing to the gate of both main NMOS and PMOS power transistors in a charge pump to reduce the channel resistance. The proposed circuit is fully implemented in a standard 0.18 mu m CMOS process, and the measurement result shows that a minimum input voltage of 190 mV is achieved and output power increases by 181% compared with the conventional forward-body-bias scheme at a 300 mV input voltage. The proposed scheme achieves a maximum efficiency of 59.2% when the input voltage is 390 mV and the output current is 320 nA. The proposed circuit is suitable as a start-up circuit in ultralow power energy harvesting power management applications to boost-up from below threshold voltage. (C) 2018 The Japan Society of Applied Physics.