An electronic device may have a display that has column driver circuitry for providing data line signals to data lines in an array of display pixels. Gate line signals on gate lines in the array and the data line signals may be used in controlling the array to display images for a user of the electronic device. The column driver circuitry may include voltage divider circuitry such as a chain of resistors with reference voltage nodes. The nodes may be provided with reference voltages from corresponding input pins. During normal operation of the column driver circuitry, a voltage supply may supply a set of column driver voltage divider reference voltages to the input pins. During power state transitions when power supply lines for the column driver circuitry might be subjected to undesirable current surges, the voltage supply may be used in supplying transitional voltages to the input pins.