Patent ID: 7893857

Claim:
An analog to digital converter, comprising: a reference voltage generating unit receiving an external voltage and outputting M number of reference voltages (M being a natural number); a reference voltage selecting unit outputting N number of reference voltages in response to a control signal, N being less than the number of the M reference voltages outputted by the reference voltage generating unit (N being a natural number); and a digital signal output unit comparing each of the N reference voltages outputted by the reference voltage selecting unit with an externally inputted analog input signal to output a comparison result as an N-bit digital signal, wherein the N-bit digital signal is fed back to the reference voltage selecting unit as the control signal, wherein the reference voltage selecting unit comprises: a transfer unit transferring N number of reference voltages selected from the M number of reference voltages from the reference voltage generating unit to the digital signal output unit; and a decoding unit decoding the control signal to output the control signal as a decoding signal for controlling the transfer unit.