High-efficiency charge-pump circuits with large current output for mobile equipment applications

This paper presents improved versions of three-stage positive-output and tw o-stage negative-output Dickson charge-pump circuits which are intended to replace switching regulators in video-product CCD driver applications (wher e 12 V and -6.5V are needed), and are designed and fabricated in a custom C MOS process. From a power supply V-dd of 4.0 to 5.5 V, the positive charge pump generates a positive output voltage of greater than 3.9(Vdd), while th e negative charge pump generates a negative voltage of greater than -1-9(Vd d), both with efficiencies of greater than 94% at 2 mA output currents.