Patent ID: 6995703
Filing Date: 2006-02-07
Classification: H03M

Abstract:
1. An analog-to-digital converting circuit comprising: a first analog-to-digital converting part for converting an input analog value into a digital value of a predetermined number of bits; a first digital-to-analog converting part for converting the digital value output from said first analog-to-digital converting part into an analog value; a first subtracting part for outputting a difference between the analog value output from said first digital-to-analog converting part and the analog value input to said first analog-to-digital converting part; a first amplifying part for amplifying an output from said first subtracting part; a second analog-to-digital converting part for converting an analog value output from said first amplifying part into a digital value of a predetermined number of bits; a second digital-to-analog converting part for converting the digital value output from said second analog-to-digital converting part into an analog value; a second amplifying part for sampling an output from said first amplifying part and amplifying the sampled output; a second subtracting part for outputting a difference between the analog value output from said second digital-to-analog converting part and the analog value output from said second amplifying part; a third amplifying part for amplifying an output from said second subtracting part; a first feedback path for feeding an output from said third amplifying part to said first analog-to-digital converting part; a second feedback path for feeding an output of said third amplifying part to said second analog-to-digital converting part; a first switch for enabling and disabling feedback to said first analog-to-digital converting part on said first feedback path; a second switch for enabling and disabling feedback to said second analog-to-digital converting part on said second feedback path; a control part for controlling on/off of said first and second switches, wherein said control part effects control so that conversion steps are performed in parallel by said first analog-to-digital converting part and said second analog-to-digital converting part, by turning one of said first and second switches on while the turning the other off and by switching between on and off of said switches at regular intervals.