a problem arises with related art liquid crystal displays in that the amount of power consumed will not be reduced any further , as a voltage generator circuit to supply power is kept activated . an exemplary method for driving a display uses a first plurality of operational amplifiers to generate a first plurality of voltages of different levels associated with a first plurality of grayscale levels displayable in the display so as to provide the display with a second plurality of grayscale levels out of the first plurality of grayscale levels . the method includes activating a second plurality of operational amplifiers corresponding to the second plurality of grayscale levels out of the first plurality of operational amplifiers , and deactivating remaining operational amplifiers other than the second plurality of operational amplifiers .