A Charge Pump Based Power Management Unit With 66%-Efficiency in 65 nm CMOS

Abstract

This paper presents a single stage power management unit that includes an enhanced stage-switch Dickson charge pump (DCP) to boost and regulate a low input voltage. A new switching mechanism is presented to significantly reduce the losses encountered in conventional DCP switches. Frequency and stage modulation are utilized in the proposed design. The stage modulation provides different gain levels (coarse) and the frequency modulation tunes the voltage level and regulates the output voltage based on a pre-determined reference voltage. Using four stages charge pump, silicon measurement results in 65 nm CMOS technology show a maximum efficiency of 66% at input voltage of 0.7 V and output power of 27 μW. The system supports a range of load current between 0.1 μA − 34 μA with a maximum operating frequency of 1.8MHz. The proposed system supports an input voltage range from 0.55 to 0.7 V which can be used in energy harvesting applications such as solar and thermal harvesting.