An apparatus for generating a VCOM voltage in a display device includes first and second buffer amplifiers and a charge pump. The first buffer amplifier is biased with high and low rail voltages for generating the VCOM voltage. The second buffer amplifier generates the high rail voltage at an output node not connected to an external capacitor. The charge pump generates the low rail voltage by charge pumping directly from an external power supply voltage. Alternatively, a charge pump and a comparator are used for generating the VCOM voltage at an output of the charge pump. The comparator generates a charge pump control signal from comparing the VCOM voltage with a reference voltage.