An analog to digital converting device includes a first digital conversion (ADC) circuit configured to convert an inputted analog signal into a first digital signal, a first multiplying digital to analog converting (MDAC) circuit configured to amplify a difference between a first converted signal and the inputted analog signal, a second ADC circuit configured to convert an output of the first MDAC circuit into a second digital signal, a second MDAC circuit configured to amplify difference between a second converted signal converted from the second digital signal and the output of the first MDAC circuit, a third ADC circuit configured to convert an output of the second MDAC circuit into a third digital signal, and a common amplifying circuit shared by the first and the second MDAC circuits, wherein the common amplifying circuit consumes current based on which MDAC circuit the common amplifying circuit operates with.