CASCADE A/D CONVERTER

PROBLEM TO BE SOLVED: To actualize the cascade A/D converter which can prevent errors due to noise from being generated. SOLUTION: This cascaded A/D converter constituted by cascading in stages comparators 8a to 8d, which convert analog input signals into digital signals, latching circuits 9a to 9d which hold the outputs of the comparators 8a to 8d, D/A converters which reconvert the outputs of the comparators 8a to 8d into analog signals, and subtracters 11d to 11f which subtract the outputs of the D/A converters from the analog signals is improved. This device has a combining circuit 60 which puts together variation waveforms of the codes of the comparators 8a to 8d, code change point vicinity detecting means which input the variation waveform of the composing circuit 60 and detect changes in the codes of the comparators 8a to 8d with width of code change point vicinity detection of >=2 stages, and an error-correcting circuit which removes noise generated at change points of the codes according to the outputs of the code change points vicinity detecting means.