Design of charge pump circuit in low-voltage CMOS process with suppressed return-back leakage current

A new charge pump circuit has been proposed to suppress the return-back leakage current without suffering the gate-oxide overstress problem in low-voltage CMOS process. A test chip has been implemented in a 65-nm CMOS process to verify the proposed charge pump circuit with four pumping stages. The measured output voltage is around 8.8 V with 1.8-V supply voltage, which is better than the conventional charge pump circuit with the same pumping stages. By reducing the return-back leakage current and without suffering gate-oxide reliability problem, the new proposed charge pump circuit is suitable for the applications in low-voltage CMOS IC products.