A system for displaying images is provided. A capacitor type digital-to-analog converter is coupled between a first node and a second node and generates a first analog signal according to a digital signal with N bit data. An analogue buffer is coupled between the second node and a third node and generates a second analog signal according to the first analog signal and a bias voltage. A first switch is coupled between a predetermined voltage and the second node. A second switch is coupled between the first node and the third node. A third switch is coupled between the third node and an analog output signal. The second switch is turned on and the third switch is turned off when the first switch is turned on, and the first and second switches are turned off when the third switch is turned on.