Patent ID: 6778124
Filing Date: 2004-08-17
Classification: H03M

Abstract:
An analog/digital converter for converting an analog voltage to N bits of a digital signal, comprising:(2Nâˆ’1) comparing means, each comparing means having a first input terminal and a second input terminal; reference voltage outputting means for dividing a differential voltage of a top voltage and a bottom voltage into at least (2N) sections and outputting at least (2Nâˆ’1) calibration reference voltages, each of the (2Nâˆ’1) calibration reference voltages applied to the second input terminal of a corresponding comparing means of the (2Nâˆ’1) comparing means, in a calibration mode; calibration voltage outputting means for outputting a ramp-like voltage to the first input terminal of each of said (2Nâˆ’1) comparing means in the calibration mode; calibrating means for selecting a corresponding reference voltage to be supplied to the second input terminal of the corresponding said comparing means causing the corresponding said comparing means to invert the corresponding said calibration reference voltage output from said reference voltage outputting means supplied to its second input terminal, when the ramp-like voltage of said calibration voltage outputting means reaches the corresponding said calibration reference voltage supplied to the second input terminal of the corresponding said comparing means; and reference voltage applying means for applying said corresponding reference voltage selected by said calibrating means to the second input terminal of the corresponding said comparing means.