A new CMOS charge pump for low voltage applications

A new charge pump, which can operate with very low supply voltages, is proposed. The MOS transistors are used as charge transfer switches (pass gates) to eliminate the effect of the threshold voltage in the pumping gain of each stage. The MOS switch of each pumping stage is controlled by the output of a dynamic inverter established in the same stage; however, the control voltage of that inverter is derived from the preceding stage. This forward control scheme considerably reduces the risk of reverse current and eliminates the need for extra circuitry, which is necessary for establishing the initial node voltages. Simulation results show that the proposed charge pump has higher pumping gain compared to other published charge pumps.