A display driver includes gamma curve control circuitry and a converter controller. The gamma curve control circuitry is configured to generate a first gamma curve for a first display brightness value (DBV), and a second gamma curve for a second DBV lower than the first DBV. The converter controller is configured to control a digital-analog converter (DAC) configured to perform digital-analog conversion of an input image data. Further, the converter controller is configured to adjust an analog signal voltage amplitude of the DAC based on a range of an output voltage associated with the second gamma curve.