Pipelined ad converter

A pipelined AD converter comprising:

• a plurality of cascaded conversion stages,
• wherein each of the plurality of conversion stages includes:
• an analog-to-digital conversion circuit for converting an input voltage from the preceding stage to a digital code;
• a digital-to-analog conversion circuit for converting the digital code obtained by the analog-to-digital conversion circuit to an intermediate voltage;
• and
• a plurality of charge operation circuits connected in parallel with each other, each having:
• a capacitor section for sampling the input voltage;
• and an op-amp for amplifying a mixed voltage of the input voltage sampled by the capacitor section and the intermediate voltage obtained by the digital-to-analog conversion circuit, and
• the op-amps of the plurality of charge operation circuits have a same configuration, and
• the capacitor section of each of the plurality of charge operation circuits has a capacitance value corresponding to the current drive capability of the op-amp of the charge operation circuit.