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.