Ad converter

An analog-to-digital converter comprising:

• a capacitive digital-to-analog converter;
• a comparator into which an output of the capacitive digital-to-analog converter is input;
• and
• a control logic unit configured to control the capacitive digital-to-analog converter on a basis of an output of the comparator,
• wherein the capacitive digital-to-analog converter includes
• a first capacitor as a bit capacitor, and
• at least one second capacitor connected to the first capacitor, and
• an analog input voltage and a power supply voltage or a ground potential are able to be selectively applied to the second capacitor.

An analog-to-digital converter comprising:

• a digital-to-analog converter;
• a comparator into which an output of the digital-to-analog converter is input;
• a control logic unit configured to control the digital-to-analog converter on a basis of an output of the comparator;
• a decoder;
• and
• an addition unit,
• wherein the control logic unit is configured to determine an additional bit while changing, at least once in units of least significant bits, the output of the digital-to-analog converter to a plus side or a minus side after determining a least significant bit,
• the decoder is configured to output a decoder output according to the least significant bit and the additional bit, and
• the addition unit is configured to add the decoder output to data including bits from a most significant bit to the least significant bit.

An analog-to-digital converter comprising:

• a digital-to-analog converter;
• a comparator into which an output of the digital-to-analog converter is input;
• a control logic unit configured to control the digital-to-analog converter on a basis of an output of the comparator;
• and
• a low-bit analog-to-digital converter with the number of bits lower than the number of bits of a digital output of the analog-to-digital converter,
• wherein the low-bit analog-to-digital converter is configured to output a first digital output signal and a second digital output signal on a basis of an analog input voltage,
• the second digital output signal is smaller than the first digital output signal by 1 in decimal, and
• a high-order bit is determined on a basis of an output of the low-bit analog-to-digital converter, and an output voltage of the digital-to-analog converter at start of successive approximation for bits following the high-order bit is determined.