A charge pump circuit includes at least one stage between an input end and an output end. The at least one stage includes a first CMOS transistor coupled with a first capacitor and a second CMOS transistor coupled with a second capacitor. The at least one stage is capable of receiving a first timing signal and a second timing signal for pumping an input voltage at the input end to an output voltage at the output end. During a transitional period of the first timing signal and the second timing signal, the at least one stage is capable of substantially turning off at least one of the first CMOS transistor and the second CMOS transistor for substantially reducing leakage currents flowing through at least one of the first CMOS transistor and the second CMOS transistor.