Recycling A/D converter

A recycling A/D converter comprising:

• an A/D conversion circuit;
• a capacitor array circuit comprising a plurality of arrayed capacitors, each arrayed capacitor having a common electrode connected to a common line and a non-common electrode selectively connectable to either a first reference voltage line and a second reference voltage line in response to a conversion result of said A/D conversion circuit;
• an operational amplifier having an input terminal connected to said common line;
• an integrating capacitor connected between said input terminal and an output terminal of said operational amplifier;
• an integration initializing circuit for initializing said integrating capacitor;
• a circuit arrangement for inputting an output voltage of said operational amplifier to said A/D conversion circuit and to said non-common electrodes of said arrayed capacitors;
• a first switching circuit provided between said common line and said input terminal of said operational amplifier;
• and
• a second switching circuit provided between said common line and said first reference voltage line,
• wherein, in the A/D conversion of a third or succeeding step, charge setting of said arrayed capacitors is implemented based on the output voltage of said operational amplifier by closing said second switching circuit under a condition where said first switching circuit is opened, and then said integrating capacitor is initialized by said integration initializing circuit.