High efficiency four-phase All PMOS charge pump without body effects

In this paper, a four-phase all PMOS charge pump based on the voltage doubler structure is proposed. The proposed charge pump is designed in 1.8 V 0.18 mum standard CMOS process with high voltage boosting efficiency and little output ripple. Moreover, it solves the voltage overstress problem which exists in the conventional charge pump and eliminates the body effect as well by means of adding two auxiliary substrate switching PMOS transistors. The simulation results show that the proposed charge pump circuits have an improvement about 93.2% compared with the original two-phase Dickson charge pump and an improvement about 28.2% compared with the negative four-phase Dickson charge pump when the supply voltage is 1.8 V. Moreover it can even work as long as the supply power voltage is larger than the threshold voltage, which makes it quite suitable to be utilized in low supply voltage applications.