A single-chip column driver for organic light emitting diode (OLED) display is disclosed. Instead of using two column drivers for dual scan, the present invention uses one column driver driving both the upper and the lower OLED panels. The column driver has a two set of output circuitry: one for driving the upper panel and the other for driving the lower panel. The single chip solution of the present invention eliminates the problem of display uniformity without increasing the part count. The invention also enables independent control of RGB without further increasing the part count.