Patent ID: 6583746
Filing Date: 2003-06-24
Classification: H03M

Abstract:
An A/D converter comprising:a capacitor for removing a DC component of an analog input signal; a first DC voltage generator for generating a DC voltage controlled in response to a feedback control voltage, and for applying the DC voltage to the analog input signal passing through said capacitor; a first input buffer for temporarily holding the analog input signal passing through said first DC voltage generator; an A/D core that generates a plurality of reference voltages and an intermediate voltage of the reference voltages, and that converts the analog input signal passing through said first input buffer into a digital output signal on the basis of the reference voltages; a second DC voltage generator for generating, in response to the feedback control voltage, a same DC voltage as the DC voltage said first DC voltage generator generates; a second input buffer consisting of a replica of said first input buffer, for temporarily holding the DC voltage said second DC voltage generator generates; and an operational amplifier for supplying the feedback control voltage to said first DC voltage generator and said second DC voltage generator to match the DC voltage passing through said second input buffer to the intermediate voltage of the reference voltages said A/D core generates.