A charge pump circuit includes a voltage input port, a voltage output port, a plurality of charge pump units cascaded between the voltage input port and the voltage output port, a clock signal source, and N clock delay elements. The clock signal source generates a main clock signal and the N clock delay elements generate clock signals received by the charge pump units by delaying the main clock signal. The main clock signal received by the first charge pump unit has a rising edge leading a rising edge of the last clock signal received by the last charge pump unit, and a falling edge lagging the rising edge of the last clock signal. Each of the charge pump units includes two sets of inverters with delay elements for generating two complementary clock signals.