An analog-to-digital converter (ADC) is provided. The ADC includes a reference voltage generator configured to generate reference voltages, an analog to digital converter core configured to receive an input signal and the reference voltages and to generate a digital signal representative of the input signal, the digital signal having a number of bits, and a controller configured to determine a quality of the input signal, and, based on a quality of the input signal, to control the number of bits of the digital signal and values of the reference voltages.