Analog-to-digital converter

An analog-to-digital converter, comprising:

• a sampling unit configured to sample differential input signals to output a differential sampled signal, the differential sampled signal having a first sampled signal and a second sampled signal;
• a reference signal generator configured to generate a first reference signal and a second reference signal;
• a plurality of preamplifiers each configured to amplify the differential sampled signal to output a differential amplification signal having a first amplified output and a second amplified output,
• the preamplifiers each having
• a first differential amplifier configured to amplify the first sampled signal by using the first reference signal, and
• a second differential amplifier configured to amplify the second sampled signal by using the second reference signal,
• the first amplified output being based on an output of the first differential amplifier and the second reference signal,
• the second amplified output being based on an output of the second differential amplifier and the first reference signal;
• a plurality of comparators each configured to compare the first amplified output and the second amplified output with each other;
• an encoder configured to generate a binary code based on comparison results of the plurality of comparator;
• and
• a correction controller configured to control operations of the first differential amplifier and the second differential amplifier based on the binary code generated by the encoder unit and control common-mode voltage levels of the first reference signal and the second reference signal or common-mode voltage levels of the first sampled signal and the second sampled signal in accordance with the operations of the first differential amplifier and the second differential amplifier.